Simple....
you have:

You're trying to find b..so isolate it...

leaving you
a=c*b
still not done....


Thus, your answer.
Answer: 12
Step-by-step explanation: Pythagorean theorem
Answer:
C
Step-by-step explanation:
Answer:
19x+8
Step-by-step explanation:
1) distribute the term outside the parenthesis to each term inside:
4*3x=12x
4*2=8
12x+8-7x
2) 12x+7x=19x
19x+8
Hope this helps!