You are not logged in.
Hi zee-f;
Please recheck your work that answer is not what I am getting.
Subtract the top one from the bottom equation.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
Offline
hi zee-f
if you would like to do this using the elimination than it would be like this:
Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.
Offline
for number 11 i tried to do it using the elimination method
x+y=0
3x+y=-4
4x+y=-4
4x=-4
x=-1
3x-1+y=-4
3x-1
-3+y=-4
-3+3+y=-4+3
-3-3=0
0+y=-4+3
y=-4+3
y=-1
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
Offline
thanx guys
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
Offline
hi zee-f
look at posts #26 an #27
Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.
Offline
am ganna need help doing these in the elimination method
12. 4x + 3y = -15
y = x + 2
13. x + 2y = -4
4y = 3x + 12
14. y = 2x
x + y = 3
15. x = 3 - 3y
x + 3y = -6
16. y = -2x + 1
y = x - 5
17. y = (1/2)x - 3
y = (3/2)x 1
18. x + y = 2
4y = -4x + 8
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
Offline
hi zee-f
you should learn when it's better to use substitution method.for example , in 12) its easier just to substitute x from the second equation into the first one.
Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.
Offline
Hi zee-f;
14,15,16,17 just subtract the first equation from the second. In each case that will reduce the simultaneous set to a single linear equation.
I believe that we have already done 17 and 18.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
Offline
hey anonimnystefy yeah it is really much easier to do it in the substitution method but am asked to do the following for an online algebra course she wants me to show in the elimination method and am finding it really hard
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
Offline
Did you try what I suggested in the post right above yours?
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
Offline
bobbym thanx
ooh and i was wondering is this first step correct 4x+3y-x+2=-15
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
Offline
If that is number 12 then you did not use elimination.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
Offline
4x + 3y = -15 + 2 + -1x
Combine like terms: -15 + 2 = -13
4x + 3y = -13 + -1x
4x + 3y = -13 + -1x
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add 'x' to each side of the equation.
4x + x + 3y = -13 + -1x + x
Combine like terms: 4x + x = 5x
5x + 3y = -13 + -1x + x
Combine like terms: -1x + x = 0
5x + 3y = -13 + 0
5x + 3y = -13
Add '-3y' to each side of the equation.
5x + 3y + -3y = -13 + -3y
Combine like terms: 3y + -3y = 0
5x + 0 = -13 + -3y
5x = -13 + -3y
Divide each side by '5'.
x = -2.6 + -0.6y
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
Offline
hi zee-f
What you did there isn't correct.
Elimination method is about eliminating one of the two variables.
So it would be like this:
Last edited by anonimnystefy (2011-06-27 10:13:05)
Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.
Offline
thanx alot its just the elimination method is sooo much harder then the substitution
i tried to do this one
in the elimination
x + 2y = -4
4y = 3x + 12
3x+12=4y
x+2y=-4
4x+14y=0
4x=-14y
x=-3.5y
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
Offline
hi zee-f
i think your understanding things the wrong way.
first of all you cant say that 12+2y=14y.
second like i said in post#39 you have to get rid of either x or y so that you can calculate the other one.
look again at post #39 lines 5,6,7 in latex.you'll see that the y is gone from one of the equations leaving only the x.then we can calculate x like in a normal equation.
Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.
Offline
so should i subtract instead ??
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
Offline
what you first have to do is multiply the equations so that coefficients with x become the same.
Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.
Offline
Add '-2y' to each side of the equation.
x + 2y + -2y = -4 + -2y
Combine like terms: 2y + -2y = 0
x + 0 = -4 + -2y
x = -4 + -2y
Simplifying
x = -4 + -2y
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
Offline
i'llshow you what i mean in this problem and then try to do the next one just like that.
Last edited by anonimnystefy (2011-06-28 02:35:56)
Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.
Offline
ok so like i totaly drag i know but i tried like when i started this is what i did
y=2x
x+y=3
y=2x
x+y=3
y=3-x
y=2x
3-x+2x=y
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
Offline
Hi zee-f;
How are you today? You did not do any eliminating over there.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
Offline
again you need to get rid of y.and you still have y in your equation.
Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.
Offline
hi zee-f
y=3-x
y=2x
So y is equal to two things. Put the two things equal to each other.
Not
3-x+2x=y
But rather
3-x = 2x
Now the 'y' is 'eliminated'.
Hope that helps
Bob
Last edited by Bob (2011-06-28 03:37:25)
Children are not defined by school ...........The Fonz
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you! …………….Bob
Offline
hey:)
so i did numbers 15-18 i tried to do them this is what i got
15#-
x=3-3y
x+3y=-6
x=3-3y
-3 -3
3-x=3y
x+3y=-6
3-x=3y
x+3y=-6
4x-3y+x=9y
3x-3y=9y
3x=6
x=2
#16- y=-2x+1
y=x-5
y=3x+6
y=3x+6
x=2
y-6=3x
y-6=3x
y=-3x
x=2
#17- y=1/2x-3
y=3/2x-1
3/2x-1-1/2x-3=y
1x--4=y
#18-
x+y=2
4y=-4x+8
-4x+8=4y
x+y=2
-3x+8y=6y
-3x=-2y
One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3
Offline