Question

I need help with 7-10 please!

Answer 1

7:
3/8 = 6/x
3x = 48
x = 16

8:
4/5 = (x+7)/40
160 = 5x + 35
5x = 125
x = 25

9:
3/8 = 12/(x-3)
3x - 9 = 96
3x = 105
x = 35

10:
4/1 = (3x+6)/x
4x = 3x + 6
x = 6