2×-1.8=×+2.4 3×-2(10-×)=15 (2×+3)×2=5×-4 18÷4×-3=9 (4-×)x7=(×-4)x9

问题描述:

2×-1.8=×+2.4 3×-2(10-×)=15 (2×+3)×2=5×-4 18÷4×-3=9 (4-×)x7=(×-4)x9

2×-1.8=×+2.4
x=2.4+1.8
x=4.2
3×-2(10-×)=15
3x-20+2x=15
5x=35
x=7
(2×+3)×2=5×-4
4x+6=5x-4
5x-4x=6+4
x=10
18÷4×-3=9
18-12x=36x
48x=18
x=3/8
(4-×)x7=(×-4)x9
16(x-4)=0
x=4