Question

помогите!!! очень надо

Answer 1

15*x(дробь)12=90
5x(дробь 4)=90
5x=360
x=72

Answer 2

15 × ( x : 12 ) = 90
x : 12 = 90 : 15
x : 12 = 6
x = 6 × 12
x = 72
______________
15 × ( 72 : 12 ) = 90