12X-8X=7.24X=7.2X=7.2/4X=1.8
12x-8x=7.2 4x=7.2 x=1.8
12X-8X=4X=36/5X=9/5=1.8
12X-8X=7.24x=7.2x=7.2÷4x=1.8
12x-8x=7.2解:12x-8x=4x=7.2 7.2除以4=1.8