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jxharmon

Member

Registered: 2007-01-08

Posts: 104

solve system by substitution

I am having trouble with this:  it is to be solved by subsitition 4x-12y=5; -x+3y=-1

4(-3y + 1) -12 y = 5; -12y +4 -12y =5;  24y +4 =5  24y= -4+5; 24y=1 y=1/24 am I doing this right??

luca-deltodesco

Member

Registered: 2006-05-05

Posts: 1,470

Re: solve system by substitution

yes, it is:

4x - 12y = 5

12y = 4x - 5
y = 1/3x - 5/12

-x + 3y = -1
3y = -1+x
y = -1+1/3x

the lines are parralel with different intercepts, there are no x,y that satisfy both equations

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jxharmon

Member

Registered: 2007-01-08

Posts: 104

Re: solve system by substitution

Thanks I thought I had totally lost it  I appreciate all the help