Question 125029
Define the variables any way you want, as long as you are consistent, and then solve the equation. The one that works best with your brain is the best for you. This one is best for mine:
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Let x be the son's age 2 yrs ago.
Let y be the father's age 2 yrs ago.
Both these variables are consistent (2 yrs ago). You could have made them equal to the present or three yrs from now. You would have had different equations in those cases but the answers (if ou did it right) would have been the same.
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A) y=4x 2 yrs ago
B) y+5=3(x+5) 3 yrs from now.
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Substitute 4x for y in B):
4x+5=3x+15
4x-3x+5-5=3x-3x+15-5
x=10
A) y=4*10
y=40
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So the son is now 12 and the father 42.
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Ed