Simplify:
(-9x) - (7+3x)

A) -12x
B) -12 + 7
C) -12x - 7
D) -x - 7

C.)-12x-7

Step-by-step explanation:

-9x-7+3x

-3x    -3x

-12x-7

they charge the same amount at 20 minutes.

step-by-step explanation:

let's call the solutions x₁ = (5 - 2√7)/3 and x₂ = (5 + 2√7)/3

then the equation is (x-x₁)(x-x₂) = 0

if you fill that in you get a lot of numbers which you can recognize as ax²+bx+c=0.

step-by-step explanation:

you can see that a=1 (there is just an x²)

b = (-5 -2√7 + 2√7 - 5)/3 = -10/3

c = -2√7)/3 ) * (-5+2√7)/3) = -1/3

so your answer is 3x^2 – 10x – 1 = 0