If segment AB is perpendicular to segment CD, then a right angle (90°) is formed.
7x + 27 = 90
7x = 63
x = 9
10 books cost $30. To figure it out, it's just 3 times the number of books. XD
Answer:
3
Step-by-step explanation:
159-12=147-12=... keep going until you get to
15-12=3
