Question

In a quadratic equation, how do you know when to change the outside number to a positive?

Answer 1

give an example

Answer 2

Like when you plug b into the formula outside of the square root sign, you're supposed to change it to a negative, but sometimes the answers are positive? Hopefully that makes sense :P

Answer 3

include the operator

Answer 4

in general:

ax^2 + bx + c is a quadratic equation, but b can be negative

ax^2 + (-b)x + c = ax^2 -bx + c

Answer 5

x^2 - 4x + 7

b = -4
---------------

2x^2 +2x - 1

b = +2
----------------

1/3 x^2 - 4/5 x + 3

b = -4/5

etc ....