b) ( 7, 21)
Step-by-step explanation:
5(7)=2(21)-7
35=42-7
35=35
Answer:
Pythagorean theorem 
Step-by-step explanation:

First Step: Leave "x" alone, pass the 3 to the other side
X= 10+3
Second Step: Add 10 plus 3
X= 13
So your answer is: x=13
Answer:
C) -2 ≤ x ≤ 2
Step-by-step explanation:
Domain is the set of x-values that can be inputted into function f(x).
We see that our x-values span from -2 to 2. Since they are both closed dots, we include them in the domain:
[-2, 2] or -2 ≤ x ≤ 2