The answer is -4k^2 - 21k - 20! so sorry if I’m wrong but it’s the answer I got :>
Answer:

Step-by-step explanation:
To isolate r, we're going to need to do some algebraic manipulation.

Multiply both sides by r:

Divide both sides by a:

Hope this helps!
Yes to both, and for future help, if you find a common denominator(the bottom one) by multiplication and one is higher, boom you have your answer.
Answer:
Step-by-step explanation:
um i think its c but im not fully sure