Question

Alfonso is 8 years older than Ashley. Five years ago Alfonso was three times as old as Ashley. How old is Ashley now

9
17
8

Answer 1

98

Answer 2

Let x = Ashley's age now and y = Alfonso's age now. How old was Ashley 5 years ago? How old is Alfonso now? Can you write these expressions?

Answer 3

x-5

Answer 4

y=3x

Answer 5

So 5 years ago Ashley was x-5. What was Alfonso's age then? Note: Five years ago Alfonso was three times as old as Ashley.

Answer 6

so =3x-5

Answer 7

Close. y-5 => Alfonso's age five years ago and 3 (x-5) => three times Ashley's age five years ago\[y-5=3(x-5)\]

Answer 8

What about Alfonso's age now in terms of Ashley's age now?

Answer 9

y=3x-10

Answer 10

right

Answer 11

That is the equation for theirs ages 5 years ago. However, now Alfonso is 8 years older than Ashley so \[y=8+x\] Understand?

Answer 12

o_0

Answer 13

When you have two unknowns (x,y) you need two equations.\[y=3x-10\]\[y=8+x\] Now substitute the second equation into the first equation (or vice versa) for y.\[8+x=3x-10\]Now solve for x.

Answer 14

thx x=9

Answer 15

Yep. So Alfonzo's age is 17 (Ashley's age plus 8) but 5 years ago, Ashley was 4 and Alfonso was 12, three times older than Ashley was then.

Answer 16

You're welcome.