I am assuming you wrote the problem wrong. Is it a^2?
A^2 -4A-21=0
(A-7)(A+3)=0
A=7 A=-3, ignore the negative number because it doesn't make sense if you plug in for a.
length=a+3=7+3=10
Width=7=a
The answer might be 39,600
The chef can make 42 casseroles no remainder
Answer:
The width of the interval would increase.
Step-by-step explanation: