Question 678735
Let X = Evan's current age
Cody is twice as old as Evan so:
Cody's current age = 2X

X-7= Evan's age 7 yrs ago
2x-7= Cody's age 7 yrs ago

the sum of their ages 7 yrs ago was 10
so add them and set them equal to 10
x-7+2x-7=10
combine like terms
3x-14=10
add 14 to both sides
3X=24
divide both sides by 3
X=8

Cody's current age is 2X  
2(8)
16

answer:  Evan is 8 yrs old and Cody is 16 years old