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1. A woman is four times as old as her son. In 5 years time, she will be three times as old as her son. How old is the woman?
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2. The sum of the interior angles of an octagon is equal to?
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3. Solve the simultaneous equations: 3b + 8a -1 =0 and 12-a+ 2b =0.
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2. The sum of the interior angles of an octagon is equal to?
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The sum of the interior angles of any polygon can be found using the formula: (n-2) • 180 degrees, where n is the number of sides or vertices in the polygon.
For an octagon, which has 8 sides, we can use this formula:
(8-2) • 180 = 6 * 180 = 1080 degrees.
Answer: 1080 degrees.
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3. Solve the simultaneous equations: 3b + 8a -1 =0 and 12-a+ 2b =0.
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3b + 8a - 1 = 0...equation A
a + 2b = 0...equation B
Rewrite equation A this way: 8a + 3b = 1.
We now have:
8a + 3b = 1
a + 2b = 0
Solve equation B for a.
a + 2b = 0
a = - 2b
Plug -2b for a in equation A to find b.
Can you take it from here?
This is called the substitution method.
Last edited by mathxyz (2024-05-21 08:51:55)
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1. A woman is four times as old as her son. In 5 years time, she will be three times as old as her son. How old is the woman?
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Woman = 4x
Son = x
Woman in 5 years = 4x + 5.
Son in 5 years = x + 5.
4x + 5 = 3(x + 4)
Solving for x I get 10.
The Son is 10 years old.
The woman is 4(10) or 40 years old.
As you know, 40 is three times greater than 10.
Answer:
Woman is 40.
Son is 10.
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Thanks and okay i will post them in the right forum next time.
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Thanks and okay i will post them in the right forum next time.
How are you doing in terms of math?
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