解方程.1.2x-0.8

解方程.1.2x-0.8=5.27.5x+2.1x=1.92(x- 2 3 )×2= 4 5 8x+1.5×3=16.5.
2025-03-05 00:27:46
推荐回答(1个)
回答1:

(1)1.2x-0.8=5.2
1.2x-0.8+0.8=5.2+0.8
1.2x=6
1.2x÷1.2=6÷1.2
x=5;

(2)7.5x+2.1x=1.92
9.6x=1.92
9.6x÷9.6=1.92÷9.6
x=0.2;

(3)(x-
2
3
)×2=
4
5

2x-
4
3
=
4
5

2x-
4
3
+
4
3
=
4
5
+
4
3

2x=
32
15

2x÷2=
32
15
÷2
x=
16
15


(4)8x+1.5×3=16.5
8x+4.5=16.5
8x+4.5-4.5=16.5-4.5
8x=12.5
8x÷8=12.5÷8
x=1.5625.