Question

Please help me with algebra part B and C. attachment below. Will mark as brainslist. 25 points.

Answer 1

Answer:

C. $(-7x+60)(x+4)$

Step-by-step explanation:

Consider the expression $-7x^2+32x+240.$

First, note that

$a=-7\\ \\b=32\\ \\c=240$

Find the discriminant

$D=b^2-4ac=32^2-4\cdot (-7)\cdot 240=1,024+6,720=7,744\\ \\\sqrt{D}=\sqrt{7,744}=88$

Now,

$x_1=\dfrac{-b+\sqrt{D}}{2a}=\dfrac{-32+88}{2\cdot (-7)}=-4\\ \\x_2=\dfrac{-b-\sqrt{D}}{2a}=\dfrac{-32-88}{2\cdot (-7)}=\dfrac{60}{7}$

Write the factored form:

$-7x^2+32x+240=-7(x-(-4))\left(x-\dfrac{60}{7}\right)=(x+4)(-7x+60)$