1/2x-28=50 1/2x=50+281/2x=78x=78÷1/2x=156x-2/7x=15/28 5/7x=15/28x=15/28÷5/7x=3/43x-1.2=3.6 3x=3.6+1.23x=4.8x=4.8÷3x=1.6x-20%x=7.2 0.8x=7.2x=7.2÷0.8x=90.9x+1.3x=5.282.2x=5.28x=5.28÷2.2x=2.4