Answer:
x = 100
Explanation:
The area of the left square is 3600
A =s^2
3600 = s^2
Taking the square root of each side
60 =s
The area of the right square is 1600
A =s^2
1600 = s^2
Taking the square root of each side
40 =s
Adding the lengths
60+40 =x
100 =x