Standard interior door height is 80 inches.
Answer:
(x-7)/(x+2)
Step-by-step explanation:
(x-7)(x+7)/(x+7)(x+2)
(x-7)/(x+2)
<span>Simplifying
b4 = 9
Solving
b4 = 9
Solving for variable 'b'.
Move all terms containing b to the left, all other terms to the right.
Simplifying
b4 = 9
Reorder the terms:
-9 + b4 = 9 + -9
Combine like terms: 9 + -9 = 0
-9 + b4 = 0
Factor a difference between two squares.
(3 + b2)(-3 + b2) = 0</span>
Answer: 
Step-by-step explanation:
Given
It takes 20 min and 30 min for a person and his friend to paint a wall individually i.e.
In 1 min they cover 
part and 
part of wall respectively.
If the work together, 1 minute work is
Time required will be reciprocal of it
