(2.8+X)×2=10.4 2/3X+1/2X=0.4
2.8+x=10.4÷2 (2/3+1/2)x=0.4
2.8+x=5.2 7/6x=0.4
x=5.2-2.8 x=0.4÷(7/6)
x=2.4 x=12/35
X/5=0.25 2X-7.5=8.5(要验算)
x=0.25÷(1/5) 2x=8.5+7.5
x=1.25 2x=16
x=16÷2
x=8
当x=8时,左边=16-7.5=8.5=右边
12÷(5X)=6/5
5x=12÷(6/5)
5x=12×(5/6)
5x=10
x=10÷5
x=2