21-
x is 18
[tex]x + 3x + 18 = 90 \\ 4x + 18 = 90 \\ 4x = 90 - 18 = 72[/tex]
[tex]x = \frac{72}{4} =18[/tex]
22- x is 50.5
[tex]x + 58 + x + 21 = 180 \\ 2x + 79 = 180 \\ 2x = 180 - 79 = 101[/tex]
[tex]x = \frac{101}{2} = 50.5[/tex]
23- x is 196/3
[tex]2x + 8 + x - 24 = 180 \\ 3x = 24 + 180 - 8 = 196\\ x = \frac{196}{3} [/tex]
24- x is 88.5
[tex]x + 15 + x - 12 = 180 \\ 2x = 180 - 15 + 12 = 177\\ x = \frac{177}{2} = 88.5[/tex]
25- x is 131
y is 180- 131=49
good luck
