Algebra question plz how can you write the expression with a rationalized denominator ? my answer was b but i'm not sure if i'm right

We rationalize fractions in order to remove square roots from the denominator. To do so, we must multiply the numerator and denominator by the same value. 

In this case, we can multiply by  which will cancel out the cube root, leaving the denominator as 4.



The result is:



This can be reduced by pulling an 8 out from the radicand:



Furthermore:



The last option is the correct answer.

What the heck i didn’t know

First, think of what you know. you know that the number t the end of the equation will need to be subtracted because it is the money he lost from buying the lawn mower. and your first two weeks have negative profit, so that tells you that c and d are wrong. now you can plug any of the weeks into a and b to see which one works. i'll start with plugging week 1 into a.this isn't right because it says your answer for week one should be -90.so now we need to try the same thing with b.this one got you the right answer, (sometimes if you only check with one of the weeks multiple will work so you need to check with more of the weeks, but it worked out fine here)this means that b is the correct answer.let me know if you need more clarification. i hope this : )