Question 147510
(2x+1)(x)(x+3)=126 __ 2x^3+7x^2+3x-126=0


factors of 126 are 7, 3, 3, 2, 1


factors of 2 are 2, 1


testing factors shows 3 as a root of the equation, so x-3 is a factor


(x-3)(2x^2+13x+42)=0 __ the discriminant of 2x^2+13x+42 is negative, so the other two roots are not real


so, x=3 and the dimensions are L=7, H=3, W=6