(1)10x+6=12x-6
(2)12000+800x=20800
(3)10x+1-10-x=18
(1)10x+6=12x-6
(2)12000+800x=20800
(3)10x+1-10-x=18
(1)10x+6=12x-6
10x-12x=-6-6
-2x=-12
x=6
(2)12000+800x=20800
800x=20800-12000
800x=8800
x=11
(3)10x+1-10-x=18
10x+1-10-x=18
10x-9-x=18
9x-9=18
9x=18+9
9x=27
x=3
(1)移项得10x-12x=-6-6(从一边移到另一边,正的变负,乘的变除)
然后得出-2x=-12,然后把x的系数化为1!即x=6(-12÷(-2))
(2)移项800x=20800-12000(上面原理)得800x=8800
把x系数化为1得x=11(8800÷800=11)
(3)合并同类项得9x-9=11(10x-x=9x,1-10=-10)
移项得9x=27(18-9=11)化系数得x=3(27÷9=3)
1、x=6
2、x=11
3、x=3
(1)10x+6=12x-6
10x-12x=-6-6
-2x=-12
x=6
(2)12000+800x=20800
800x=20800-12000
x=9
(3)10x+1-10-x=18
10x-x=18-1+10
9x=27
x=3