Question

$(5 x {}^{2} + 3)(2x + 7) - (9x { }^{2} + 7)(x + 5$
​

Answer 1

Answer is $x^{3} - 10x^{2} - x - 14$

Step-by-step explanation:

$(5x^{2} + 3)(2x + 7) - (9x^{2} + 7)(x + 5)$

= $(10x^{3} + 35x^{2} + 6x + 21) - (9x^{3} + 45x^{2} + 7x + 35)$

Opening the Brackets we get-  

$10x^{3} + 35x^{2} + 6x + 21 - 9x^{3} - 45x^{2} - 7x - 35$

= $x^{3} - 10x^{2} - x - 14$

Answer is $x^{3} - 10x^{2} - x - 14$