13 +2.3(x-3)=8 +2(x-3) +0.8x13+2.3x-6.9=8+2x-6+0.8x0.5x=4.1x=8.2x的值是8.2
13+ 2.3(x-3)=8 +2(x-3)+ 0.8x13+2.3x-6.9=8+2x-6+0.8x2.3x+6.1=2.8x+22.8x-2.3x=6.1-20.5x=4.1x=8.2
先消除括号,方程为13+2.3x-6.9=8+2x-6+0.8x将x和常数分别移至等号两边-0.5x=-4.1消除系数得x=8.2