Find the value of x this question is for geometry

Sense we know it is a right angle, we can set the equation to equal 90

3x-9 + x+7 = 90

Combine like terms

4x - 2 = 90

Add 2 to each side

4x = 92

Divide by 4 on each side

x=23

So a straight line is called a supplementary angle, which means that it is equal to 180. The boxy thing on the left-hand side indicates that that angle is equal to 90 degrees.

The equation would be : 3x - 9 + x + 7 +90 = 180

Combine like terms : 4x + 88 = 180

Subtract 88 from both sides : 4x = 92

Divide by 4 on both sides : x = 23

for this pair of functions g(x)=x-2 and f(x)=|x| is (g o f)(a)= |a| -2

step-by-step explanation:

g(x)=x-2

f(x)=|x|

(g o f)(a)=?

(g o f)(x)=g(f(x))

(g o f)(x)=g(|x|)

(g o f)(x)=|x|-2

(g o f)(a)=|a|-2

80x^8−68x^6+16^5−20x^4−4x^3+8x^2

hope i'm right lol