Question

a is 15 years older than b. ten years ago, a was four times b ages. what are their ages now.

Answer 1

Let present age of A be x and of B be y

We are given, x = y+15 ....................................................(1)

 we are also given, (x-10) = 4(y-10)
                              (y+15-10) = 4y - 40                      [By (1)]
                           y+5 = 4y-40
                     so, 3y = 45 
                             y = 15 

so x = y+15 = 30 yrs

hence we have, Present age of A (x) = 30 yrs.
                    and, Present age of B (y) = 15 yrs.

Answer 2

Hi there.....

Let age of A be x, age of B be y
y+15=x
x-y=15........(i) (multiply by -1)

x-10=4(y-10)
x-10=4y-40
x-4y=-30.....(ii)

Add both equations:
-x+y=-15
x-4y=-30

-3y=-45
y=15

Hence x=y+15=15+15=30

Hence age of A=30 years
Age of B=15 years

Please comment if any doubt....
And please mark my answer as the brainliest!!!