Question

48=2(x+(x+7) ) , x - ?

Answer 1

4x=48-14 ; 4x=34 ; x=8,5

Answer 2

2x+2x+14=48
4x=34
x=34/4
x=8,5
или 
x+x+7=48/2
2x=24-7
2x=17
x=17/2
x=8,5