Answer:
False
Step-by-step explanation:
X = 5 goes to two different values of y so it is not a one to one correspondence. This is a relation not a function.
Answer:
25% is called a quarter of 900
Step-by-step explanation:

They are basically like groups. Take -3x+2x , Just do -3 +2 = -1 and then just add the x. So -1x. Next you have -5y+10y . Just do -5 + 10 = 5 and remember to add the x on so your final answer should be -1x + 5y
Answer:
Step-by-step explanation:
Since the ratio is 4x:4x:7x, if we add all those numbers up we get 15. Then we do 75/15 to get what x equals. So we get 5. So x equals 5. Following the rules of multiplication, you do 4(5):4(5):7(5), and simplifying that further, you get 20:20:35. If we add all those values up, we should get 75, and we do!
If you're wondering why I did 4x:4x:7x instead of 4:4:7, it's because a ratio is just a...well ratio? It's easier to visualize if you put a variable because the variable could be anything, and you would have to multiply all the given values to get the same proportions. In summery, I did it so it was easier to visualize
Paper he needs = total surface area
So to break it down into 2D shapes, that prism has 2 2D triangles, and 3 2D rectangles of different sizes.
The triangles are the same size, since you have 2, just multiply 2 by the formula for the area of a triangle: 1/2(base)(height) which is 2x1/2(5)(12) = 60
Next you'll need the area of all the rectangles: length x width. which would be (5 x 5) + (13 x 5) + (12 x 5) = 150
So the total amount of wrapping paper he'd need is 150mi^2