Question

(5x + 2)(4x2 - x + 2) = Ax3 + Bx2 + Cx + D. What are the values of B and C?

Answer 1

$(5x + 2)(4 {x}^{2} - x + 2)$

$= 20 {x}^{3} - 5 {x}^{2} + 10x + 8 {x}^{2} - 2x + 4$

$= 20 {x}^{3} + 3 {x}^{2} + 8x + 4$

$It\:is\:in\:the\:form\:of\:A{x}^{3}+B{x}^{2}+Cx+D$

$∴B = 3 \: and \: C = 8$