解方程 必采 7.8x+2.4x=20.4 2(x+1)=6 6(x-1.5)=15 4x-1解方程必采7.8x+2.4x=20.42(x+1)=66(x-1.5)=154x-12×3=100(x-5)÷3=7x-0.28x=3.6

问题描述:

解方程 必采 7.8x+2.4x=20.4 2(x+1)=6 6(x-1.5)=15 4x-1
解方程
必采
7.8x+2.4x=20.4
2(x+1)=6
6(x-1.5)=15
4x-12×3=100
(x-5)÷3=7
x-0.28x=3.6

7.8x+2.4x=20.410.2x=20.4x=22(x+1)=6(两边÷2)x+1=3x=26(x-1.5)=15 两边÷32(x-1.5)=52x-3=52x=8x=44x-12×3=1004x=100+364x=136x=34(x-5)÷3=7x-5=21x=26x-0.28x=3.6;0.72x=3.6;x=360/72;x=5...