Hi there!
a. 8x^2 - 1
(x^2 - 4x + 5) + (7x^2 + 4x - 6)
= x^2 + 7x^2 - 4x + 4x - 1
= 8x^2 - 1
b. 5x^2 + 7x - 7
(7x^2 + 4x - 6) - (2x^2 - 3x + 1)
= 7x^2 + 4x - 6 - 2x^2 + 3x - 1
= 7x^2 - 2x^2 + 4x + 3x - 6 - 1
= 5x^2 + 7x -7
Hope this helps!
ANSWER
A. 22 in
EXPLANATION
The volume of a cone is calculated using the formula:

It was given that: the volume is 2,279.64 in³
The height of the cylinder is also given as: h=18 in.
We substitute, the given values into the formula to get:




We take positive square root to get;


Therefore the diameter is 2(11) which is equal to 22 inches.
458,500 because they are 1000 apart and 500+500=1000
Answer:
im not fully sure because im a 4th grader but 52 i think.
Answer:
The answer is 24
Step-by-step explanation:
Because you add all of the numbers up and you get 24.