Question

please do this question fast​

Answer 1

Answer:

12x^4+308x³+424x²+116x-15

Step-by-step explanation:

12(x²+7x)² - 8(x²+7x)(2x-1) - 15(2x-1)²

12(x^4+27x³+49x²)-8(2x³-x²+14x²-7x)-15(4x²-4x+1)

12x^4+324x³+588x²-8(2x³+13x²-7x)-60x²+60x-15

12x^4+324x³+588x²-16x³-104x²+56x-60x²+60x-15

12x^4+324x³-16x³+588x²-104x²-60x²+56x+60x-15

12x^4+308x³+424x²+116x-15