小学方程(两边都有“x”)7×(
7×(x-1)=2x+3
7X-7*1=2X+3(前面是乘法分配)
7X-7 =2X+3
7X-7+7=2X+3+7(两边同时+7,使左边只有未知数)
7X =2X+10
7X-2X =2X+10-2X(同时-2X,使右边没有未知数)
5X =10
X =2
(x+5)×4=6×(x-5)
4X+5X =6X-6*5(乘法分配)
4X+5X =6X-30
9X =6X-30
9X+30 =6X-30+30(同时+30,后边变成只有未知数)
9X+30 =6X
9X+30-6X =6X-6X(同时-6X,是右边的6X抵消)
3X+30 =0
X =-...全部
7×(x-1)=2x+3
7X-7*1=2X+3(前面是乘法分配)
7X-7 =2X+3
7X-7+7=2X+3+7(两边同时+7,使左边只有未知数)
7X =2X+10
7X-2X =2X+10-2X(同时-2X,使右边没有未知数)
5X =10
X =2
(x+5)×4=6×(x-5)
4X+5X =6X-6*5(乘法分配)
4X+5X =6X-30
9X =6X-30
9X+30 =6X-30+30(同时+30,后边变成只有未知数)
9X+30 =6X
9X+30-6X =6X-6X(同时-6X,是右边的6X抵消)
3X+30 =0
X =-10。
收起