Question

wo years ago Adam was 6 times as old as his son. In 3 years he will be 3 1/2 times as old as his son. Find their present ages.

Answer 1

How to solve this using 2 variables?

Answer 2

what should i do next?

Answer 3

Question: **two years ago Adam was 6 times as old as his son. In 3 years he will be 3 1/2 times as old as his son. Find their present ages.
Assume age of adam now = x
adam's son age now = y.
x-2 = 6(y-2)
x+3 = 3.5(y+3)

Answer 4

sorry i made a mistake earlier, we have subtract 2 from x and y, and add 3 to both x and y (use parentheses)

Answer 5

because it says 2 years ago, both adam and his son's age decreases by 2

Answer 6

so then it becomes x-2=6y-12 and x+3=3.5y+10.5 ?

Answer 7

yes

Answer 8

now you can solve by elimination (subtract the two equations and eliminate x), or you can solve for x in both equations

Answer 9

x = 6y -10
x = 3.5y + 7.5
so they both equal to x (and so equal to each other)
6y-10 = 3.5y + 7.5
2.5y = 17.5
y = 7
x = 6*7-10 = 32

Answer 10

this problem is a good example of algebraic thinking

Answer 11

ok. thanks!