The area of a rectangular classroom is given by the trinomial a - 4a - 21. The length of the rectangle is a+3. What is the expression for the width of the classroom?
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
