a) x - 105 : 21 = 15
x - 5 = 15
=> x = 20
b) ( x - 105 ) : 21 = 15
x - 105 = 315
=> x = 420
c) 315 + ( 125 - x ) = 435
125 - x = 120
=> x = 5
a)x - 105 : 21 = 15
x - 5 =15
x =20
b) (x - 105) :21=15
x -105 =315
x =420
c) 315+ (125 - x ) =435
125 - x =-120
x =5