For this case we are asked the following question:
"What is the volume of the rubick's cube whose edge measures 3 cm"
By definition, the volume of a cube is given by:

Where:
l: Is the side or the edge of the cube
According to the statement we have:

Substituting:

Finally, the volume of the cube is 
Answer:

The first one is < because if you have 5 part of 7, you have more parts than if you have 4 parts of 7, but it’s negative so it’s the opposite
You do that dilation by multiplying every x- and y-coordinate value by 2.5.
Answer:
y=
= 0.75
Step-by-step explanation:
To subtract the second equation from the first equation, you have to divide the equation as left of the equal sign and right of equal sign then do the calculation separately. The calculation will look like this
-3x +2y = 7
-3x - 2y = 4
_____________ -
(-3x +2y) - (3x -2y) = 7 - 4
-3x + 2y + 3x + 2y = 3
4y= 3
y=
= 0.75