help me with my algebra homework!

I'm a little worried Rose. The questions you've posted here are pretty basic. If you are really having problems with them I recommend you stop by and talk to your teacher or get some tutoring help. Us giving you the answer is not going to help you pass this course.

The side is 2y-3 cm and y is 7.25, so how long is the side?
The volume of a cube is the side length that you calcualted above cubed. That means find what (S x S x S) is.

For this one you'll need to know the rules of the order of doing the arithmetic. Multiplication and division occur before addition and subtraction. Replace y in the formula with the value 7.25, then do the multiplication, followed by the subtraction.

(2)(7.25)-3 THEN, find the cube of that value.

my teacher doesnt teach and i just want to double check my answer i got 1520.875

Correct, but I bet you used a calculator.

great way to check answers is to include units. If my cube has a side that is given in cm , right. If I take a cm and cube it--that's cm^3 and that's a volume. Which is what's asked for, and I have a good indication that the answer is correct.

BTW you can take a cm^3 and convert it to gallons, cups, tablespoons, liters and so on.

Rap


Ans y=7.25 cm=7+1/4 cm =29/4 cm.
Plug in 2*7-3 cm =58/4-3 cm=58/4-12/4cm=(58-12)/4 cm=46/4 cm (11 1/2)
46/4cm=23/2cm
(23/2 cm)^3=(23/2)^3 cm^3=23^3/2^3 cm^3