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
Answer:
18 cm
Step-by-step explanation:
Answer: 13.6 or 9.2
Step-by-step explanation:
2 is the correct answer I believe
Answer: 148
Step-by-step explanation: