A rectangular prism is 18 inches long, 12 inches wide, and 12 inches deep. What is the volume of the cooler? If each volume is increased by x inches, what would be the new volume?

Question

izzy18970 · Answer

$$18*12*12=2592 $$

izzy18970 · Answer

$$(18+x)(12+x)(12+x) = 3x + 2592$$

izzy18970 · Answer

Is this correct? the chapter is building polynomials

phi · Answer

the first side (left side) is correct. but it is a messy multiplication. it's not 3x+2592

for example , just do
(x+18)(x+12)
(people usually put the "variable" first. don't have to, but that is what people do)

phi · Answer

to multiply you can do
(x+18) * x  + (x+18)*12
now distribute and combine like terms
do you know how to do that ?

izzy18970 · Answer

I got $$x^2+30x+216$$ for the first part

izzy18970 · Answer

the total would be $$x^3+42x^2+576x+2592$$

izzy18970 · Answer

Is this correct?

phi · Answer

yes, now you do
(x^2+30x+216)*(x+12)
which is 
x^2*(x+12) + 30x*(x+12) + 216*(x+12)

phi · Answer

yes, your answer looks good

izzy18970 · Answer

Did I do everything correctly?

phi · Answer

you wrote the correct result.

izzy18970 · Answer

Thank you for your help