I really need an answer, I was absent the day this was discuss and I don't know what to do here please ASAP Annie is 8 years older than Girlie. Two years ago, Annie was twice as old as Girlie. What are their present ages?

I get the first part, which is x-y=8 , but I don't get the other, I multiplied girlie's age bt two and subtract both age by 2 , then what?

1 Answer
Mar 11, 2018

Girlie is 10, Annie is 18

Explanation:

Let Girlie's age be y
and Annie's age be x

You have correctly found that x=y+8 or x-y=8

The second statement tells us that
two years ago 2y=x

Hence we solve the equations simultaneously (I have done it by substitution) to find their ages two years ago, then simply add 2 to each of their ages.

=> 2y=y+8
=> y=8
=> x=2*8 = 16

then add two to each:
y=10
x=18

Alt method:
If you are confident rearranging equations,
equation 2 can be written as: 2(y-2)=(x-2)
which removes the need to add two later.

2(y-2)=(y+8-2)
=> 2y-4=y+6
=>y=10
=> x=10+8=18