问题 解答题
解方程.
96-5x=42
8x+0.4×1.2=2.47.2-5x=3.6
9x÷3=5.42.9x+1.28=7.084x-19.5=4.1.
答案

(1)96-5x=42

96-5x+5x=42+5x

5x+42=96

5x+42-42=96-42

5x=54

5x÷5=54÷5

x=10.8;

(2)8x+0.4×1.2=2.4

8x+0.48=2.4

8x+0.48-0.48=2.4-0.48

8x=1.92

8x÷8=1.92÷8

x=0.24;

(3)7.2-5x=3.6

7.2-5x+5x=3.6+5x

5x+3.6=7.2

5x+3.6-3.6=7.2-3.6

5x=3.6

5x÷5=3.6÷5

x=0.72;

(4)9x÷3=5.4

9x÷3×3=5.4×3

9x=16.2

9x÷9=16.2÷9

x=1.8;

(5)2.9x+1.28=7.08

2.9x+1.28-1.28=7.08-1.28

2.9x=5.8

2.9x÷2.9=5.8÷2.9

x=2;

(6)4x-19.5=4.1

4x-19.5+19.5=4.1+19.5

4x=23.6

4x÷4=23.6÷4

x=5.9.

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