4X+7x+7（x+150）=8250
4x+7x+7x+150×7=8250
18x+1050=8250
18x=8250-1050
18x=7200
x=7200÷18
x=400 4X+7x+7（x+150）=8250
4x+7x+7x+150×7=8250
18x+1050=8250
18x=8250-1050
18x=7200
x=7200÷18
x=400