19. (X+5)-3
20. 2a
21.3b
22. 5y-5
23. 1/2n-15
Answer:
1) x = 15
Step-by-step explanation:
We use the Pythagorean thm for these questions. Where a and b are the legs (So order doesn't matter), and where c is the hypotenuse
1)
a² + b² = c²
9² + 12² = x²
81 + 144 = x²
x² = 225
You square root each side so you can get rid of the exponent on x.

x = 15
Answer: parallel means 2 sides that will never intersect
Step-by-step explanation:
Answer:
a - t = 2
Step-by-step explanation:
Answer: 26.7 is 13% of 89