Rearrange the equation to standard form of a quadratic equation (ax^2+bx+c=0) by switching sides: 5x^2+2x-12=0. Now, use the quadratic equation formula to solve. You should come out with x_1=sqrt61-1/5 and x_2=-1+sqrt61/5. Thus, your answer is B, or two solutions.
Area of prism = area of base * height
= ( 312 * 5 ) * 112 = 174720 cubic inch
5x+(-4)-5x=6x+4-5x
-4=x+4
x=-8
To get rid of 5x on the left side.
