215 - ( 4x + 15 ) = 128
4x + 15 = 215 - 128
4x + 15 = 87
4x = 87 - 15
4x = 72
x = 72 : 4
x = 18
4x+15=215-128=87
4x=87-15=72
x=72:2=36
x=36 nha bn
215 - ( 4x + 15 ) = 128
4x + 15 = 215 - 128
4x + 15 = 87
4x = 87 - 15
4x = 72
x = 72 : 4
x = 18
215-(4x+15)=128
4x+15=215-128
4x+15=87
4x=87-15
4x=72
x=72:4
x=18
215 - ( 4x + 15 ) = 128
4x + 15 = 215 - 128
4x + 15 = 87
4x = 87 - 15
4x = 72
x = 72 : 4
x = 18
215 - (4x + 15 ) = 128
4x + 15 = 215 - 128
4x + 15 = 87
4x = 87 - 15
4x = 72
x = 72 : 4
x = 18
215 - ( 4x + 15 ) = 128
215 - 4x - 15 = 128
200 - 4x = 128
4x = 200 - 128
4x = 72
x = 72 : 4
x = 18
215 - ( 4x + 15 ) = 128
215 - 4x - 15 = 128
200 - 4x = 128
4x = 200 - 128
4x = 72
x = 72 : 4
x = 18