2x+1=5
2x+1-1=5-1
2x=4
2x÷2=4÷2
X=2
5Y-2Y=18
3Y=18
3Y÷3=18÷3
Y=6
12X-9X=8.7
3X=8.7
3X÷3=8.7÷3
X=2.9
n+1/3=2/5
n+1/3-1/3=2/5-1/3
n=6/15-5/15
n=1/15 (15分之1)
3/5+m=7/10
3/5+m-3/5=7/10-3/5
m=7/10-6/10
m=1/10 (10分之1)
x-3/4=1/12
x-3/4+3/4=1/12+3/4
x=1/12+9/12
x=10/12
x=5/6 (6分之5)
2x+1=5
2x=5-1
2x=4
x=2
5y-2y=18
3y=18
y=6
12x-9x=8.7
3x=8.7
x=2.9
n+1/3=2/5
n=2/5-1/3
n=6/15-5/15
n=1/15
3/5+m=7/10
m=7/10-3/5
m=7/10-6/10
m=1/10
x-3/4=1/12
x=1/12+3/4
x=1/12+9/12
x=10/12
x=5/6
X=2, y=6, x=2.9, n=1/15, m=1/10 ,X=5/6
根据四则运算各部分关系来解答