Question

If A = 2x2 - 3x + 5; B = 5x + 2 and C = x2 + 3x - 7, then
19. A x B =
2) 10x3 - 11x2 - 19x - 10
1) 10x3 - 11x2 + 19x + 10
3) 10x3 + 11x2 – 19x + 10
4) 10x3 + 11x2 + 19x + 10
20
BX CE​

Answer 1

Answer:

$\mathrm{\left(2x^2-3x+5\right)\times \left(5x+2\right):\quad 10x^3-11x^2+19x+10}$

Step-by-step explanation:

$\mathrm{\left(2x^2-3x+5\right)\left(5x+2\right)}$

$\mathrm{Apply\:the\:distributive\:law:\quad \left(a+b\right)\left(x+y+z\right)=ax+ay+az+bx+by+bz}$

$\mathrm{\left(2x^2-3x+5\right)\left(5x+2\right)=2x^2\times \:5x+2x^2\times \:2-3x\times \:5x-3x\times \:2+5\times \:5x+5\times \:2}$

$\mathrm{=2x^2\times \:5x+2x^2\times \:2-3x\times \:5x-3x\times \:2+5\times \:5x+5\times \:2}$

$\mathrm{=10x^3-11x^2+19x+10}$