Find the result when you subtract (5y+9z)to(4y-7z)
A. -y-16z
B.-y+16z
C.9y+2z
D.9y-2z​

Step-by-step explanation:

It’s B

Use determinant
in form ax²+bx+c=0
when b²-4ac>0, it has 2 real roots
when b²-4ac=0, it has 1 real root
when b²-4ac<0, it has no real roots
so

we solve for no real roots
b²-4ac<0
a=3
c=7
b=-m

(-m)²-(4)(3)(7)<0
m²-84<0
add 84 both sides
m²<84
sqrt both sides
m<9.1 about
nearest integer
round down
m=9

answer is m=9