I mean it would be A and D because I don't know why they are both the same answer. If 10 books were sold yesterday, at LEAST 20 are needed to make the goal.
N^2 + n - 120 = 0
Quadratic formula
a = 1, b = 1, c = -120
n = [-1 plus or minus root(1^2 - 4(1)(-120))] / 2(1)
n = (-1 plus or minus root481)/2
n =(approximately) 10.5 or -11.5
z = -11
Steps:
8z+12 = 5z-21
Subtract 12 from both sides
8z+12-12 = 5z-21-12
Simplify
8z = 5z-33
Subtract 5z from both sides
8z-5z = 5z-33-5z
Simplify
3z = -33
Divide both sides by 3
3z/3 = -33/3
Simplify
z = -11
Hope this helps you! (:
-Hamilton1757
Answer:
The bottom left square of the triangle in 90 degrees always so take 90 + 40 giving you 130,
a Triangle has 180 degrees in total so 180 -130 = 50 degrees for the last side