Answer:
63
Step-by-step explanation:
Using the formula attached, we can setup the equation:

Then using a calculator you can solve
21 is the opposite of -21
Answer: 3/20
Step-by-step explanation:
12/80 is simplified to 3/20
Answer:
a2 – b2 = (a – b)(a + b)
(a + b)2 = a2 + 2ab + b
a2 + b2 = (a + b)2 – 2ab
(a – b)2 = a2 – 2ab + b
That's all i know- rip TvT