This is a stupid question. The teacher who asked this needs to go back to school.
A = x⁴ - 9y²
That's going to be a number. As long as it's positive we can choose any length for our rectangle L and we can compute the width by W=A/L. So the correct answer is the dimensions are L by (x⁴ - 9y²)/L.
They don't want the correct answer. They want you to factor this expression. We'll do it, but don't believe for a second this factoring somehow constrains the possible dimensions of some rectangle.
We use the difference of two squares, a²-b² = (a+b)(a-b)
A = x⁴ - 9y² = (x²)² - (3y)² = (x²+3y)(x²-3y)
Answer: x²+3y by x²-3y
it is in the smallest form!
Answer:

Step-by-step explanation:
The area of the circumference of a circle is:

We know that r is 8, so we can plug that into the formula.
However, there's a problem. We only want 3pi/4 of the circumference, not the entire circle's circumference. Therefore, we have to divide by part/whole. In this case, the part is 3pi/4, and the whole is 2pi (the entire circle is 2pi radians).

Answer:
-3(4x+3)+5x (Given) 1/2 (6k+10)+5k (given)
-12x-9+5x (distribution) 3k+5+5k (distribution)
-12x+5x-9 (associative) 3k+5k+5 (associative)
-7x-9 (Combine like terms) 8k+5 (combine like terms)
Step-by-step explanation: