Question

(5x+1/4)-(2x-1/6)=1-(3-x/12)怎么做？ 还有1-（0.7+3x/0.8)=(0.3x-1/0.4)-x

Answer 1

(5x+1)/4-(2x-1)/6=1-(3-x)/12
两边乘12
3(5x+1)-2(2x-1)=12-(3-x)
3(5x+1)+(3-x)=12+2(2x-1)
15x+3+3-x=12+4x-2
14x+6=4x+10
14x-4x=10-6
10x=4
x=4/10=2/5
第二题：
1-(0.7+3x）÷0.8=(0.3x-1)÷0.4-x
1-(0.7+3x)×5/4=(0.3x-1)×5/2-x
1-7/8-15x/4=3x/4-5/2-x
1/8+5/2=3x/4-x+15x/4
14x/4=21/8
x=21/8÷14/4
x=3/4

Answer 2

(5x+1/4)-(2x-1/6)=1-(3-x/12)
5x+1/4-2x+1/6=1-3+x/12
3x+5/12=x/12-2
36x+5=x-24
36x-x=-24-5
35x=-29
x=-29/35

1-（0.7+3x/0.8)=(0.3x-1/0.4)-x
1-0.7-3x/0.8=0.3x-1/0.4-x
0.3-30x/8=-0.7x-2.5
0.7x-3.75x=-2.5-0.3
-3.05x=-2.8
x=2.8/3.05
x=56/61