Question

Find the following product: $(x^3-2x^2+5)\times (4x-1)$

• A. $4x^3-9x^3+2x^2+20x-5$
• B. $4x^4-9x^3+2x^2+20x-5$
• C. $4x^4+9x^3+2x^2+20x-5$
• D. $4x^4-9x^3-2x^2+20x-5$

Answer 1

Answer: (B)

$4x^4-9x^3+2x^2+20x-5$

Required product is $(x^3-2x^2+5)\times (4x-1)$

Multiplying the two polynomials, we get:
$(x^3-2x^2+5)\times \left(4x\right)-(x^3-2x^2+5)\times \left(1\right)$
$=4x^4-8x^3+20x-x^3+2x^2-5$
$=4x^4-9x^3+2x^2+20x-5$
Hence, $(x^3-2x^2+5)\times (4x-1)=4x^4-9x^3+2x^2+20x-5$.