Question

n^2 + 7n − 120 = 0
using quadratic formula which is in the post below

Answer 1

Right, so we just use the equation...you have an expression in the form we need

'Dont worry about the fact that your expression has 'n' instead of 'x' btw...its just solving for a variable

\[\large ax^2 + bx + c = 0\]
Compare it to your equation
\[\large x^2 + 7x - 120 = 0\]

So we have

a = 1
b = 7
and
c = -120

Just plug those into your formula and solve for 'x'

\[\large x = \frac{-7 \pm \sqrt{7^2 - 4(1)(-120)}}{2(1)}\]