Answer:
-12
Step-by-step explanation:
50 + -20 - 6x
First combine like terms
30 -6x
Then let x=7
30 -6(7)
30 -42
36.7⁰
As the triangle is right angled :
tan of the angle = 24/32
tan of angle = 3/4
angle = 36.9⁰
2(20 + 22) = 2(42) = 84 total books