30%x=120 30x=12000 x=400
x-60%x=160 40%x=160 40x=16000 x=400
120x-20x=40 100x=40 x=0.4
50%x-33%x=34 17%x=34 17x=3400 x=200
x+130%x=460 230%x=460 230x=46000 x=200
x+1/5x=240 6/5x=240 6x=1200 x=200