Browse · MATH Print → jmc algebra intermediate Problem Let r and s be the solutions to 2x2−3x=11. Compute the value of (4r3−4s3)(r−s)−1. Solution — click to reveal Let r and s be the roots of 2x2−3x−11=0, so by Vieta's formulas, r+s=23 and rs=−211.Then r−s4r3−4s3=r−s4(r−s)(r2+rs+s2)=4(r2+rs+s2)=4[(r+s)2−rs]=4[(23)2+211]=31. Final answer 31 ← Previous problem Next problem →