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
to find the slope, we have to use the formula y2-y1 over x2-x1. Now, plug in our values; 8-28 over 6-18. Our answer becomes -20 over -12 this simplifies to 5 over 3, and there's your answer.
