Question

X + X : 5 x 7,5 + X : 2 x 9 = 315

Answer 1

X + X : 5 x 7,5 + X : 2 x 9 = 315

X + X x 1,5 + X x 4,5        = 315

X x ( 1 + 1 , 5 + 4,5 )       = 315

X x 7                               = 315

X                                     = 45

Answer 2

X+X:5x7,5+X:2x9=315

X+Xx1,5+Xx4,5=315

Xx7                 =315

X                    =45