Hello!
You can multiply (x-12) and (x+4)
x * x = x^2
x * 4 = 4x
-12 * x = -12x
-12 * 4 = -48
Now we have
x^2 - 8x - 48 = 9
Subtract 9 from both sides
x^2 - 8x -57 = 0
Use the quadratic formula
This give use the answer of
x = 4 +

Hope this helps!
Answer:
46 degrees
Step-by-step explanation:
you know that if you add 134 and x it will equal a straight line or 180 degrees. So set it up as an addition problem.
134 + x =180 subt. 134 from both sides
x=180-134
x=46 degrees
The standers slop form is y=mx+b