Question

SOMEONE PLEASE HELP....

Answer 1

Answer:

Step-by-step explanation:

$(3x+4)(x^2+px+5) \\=3x^3+3px^2+15x+4x^2+4px+20\\=3x^3+(3p+4)x^2+(15+4p)x +20$

since we know that $x^2$  in this expansion is $-23x^{2}$

thus $3p+4=-23\\3p=-27\\p=-9$

Hope that helps!