Question

What are the roots for the trinomial below? *x2 – 2x – 15O x=-5,x=-3Ox=5,x=-3Ox=3,x=5O x=-5,x=3

Answer 1

`x=5,=-3`

Explanation:

We have the following equation:

`x^2-2x-15`

We solve by factoring. We look for two numbers that product -15 and the sum is equal to -2:

`\begin{gathered} 3\cdot-5=-15 \\ 3+(-5)=-2 \\ \text{Therefore:} \\ (x+3)\cdot(x-5)=0 \\ x+3=0\rightarrow x=-3 \\ x-5=0\rightarrow x=5 \end{gathered}`