It is D i think.............
.
Answer:
30
Step-by-step explanation:
(-) (-) = +
Therefore 15 - (-15) = 15 + 15 = 30
Answer: A, C, and E! I just took this on Khan Academy! Please mark me brainliest because it it correct!
Answer:
A) X + Y = 12
B) 10Y + x = 10x + Y -18
B) 9Y = 9x -18 multiplying A) by -9
A) -9Y = 9x - 72 adding A and B we get
0 = 18x -90
x = 5
The number is 75
Double-Check
7 + 5 = 12
75 -57 = 18
Step-by-step explanation:
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
