Question

The roots of a quadratic equation are -5 and 3. Which of the following quadratic equation has these roots?

A. x²-8x+15=0
B. x²+8x+15=0
C. x²-2x-15=0
D. x²+2x-15=0​

Answer 1

D.

`{x}^(2) + 2x - 15 = 0`

Explanation:

The derive the quadratic equation from the given roots :

x^2 - (sum of roots) x + (product of roots) = 0

Roots :- -5 and 3

`{x}^(2) - ( - 5 + 3)x + (( - 5)(3)) = 0 \\ {x}^(2) - ( - 2)x + ( - 15) = 0 \\ {x}^(2) + 2x - 15 = 0`