help me MATH

54-x+23=37
77-x=37
-x=-40
x=40

20x+9=56-27x
47x=47
x=1

7x-10=50-5x
12x=60
x=5

8x+5=3x+35
5x=30
x=6

7y-4=12+5y-4
2y=12
y=6

5+7x=35+5x
2x=30
x=15

5(x+4)=x+40
5x+20=x+40
4x=20
x=5

6(x+3)-18=24
6x+18-18=24
6x=24
x=4

3(x+4)-7=20
3x+12-7=20
3x+5=20
3x=15
x=5