how do you solve the trinomial -x^2-2x+15

Question

I need help because I do not understand this topic that I am going over in math class

Answer 1

-x² - 2x + 15

 

There are two ways to solve for x.  One way is the factor into two binomials using FOIL method.  The other way is to use the quadratic formula.  Since we have a negative sign in front of the x² term, we will use the quadratic formula.

 

x = (-b ± √(b² - 4ac)) / 2a

 

The   ±   sign indicates that we use addition and subtraction, using the same formula given.  This means that you will have two solutions for x.

 

Since the quadratic formula is in the form  ax² + bx + c ,

 

a = -1

b = -2

c = 15

 

Substitute these values into the equation and you will obtain your solutions.