Question

write the root of quadratic equation x²+8x+15= a) 3,5 b) -3,5 c) -3,-5 d) 3,-5​

Answer 1

Answer:

c) -3,-5

Step-by-step explanation:

x² +8x+15=0

x² +3x +5x+15=0

x(x+3) +5(x+3)=0

(x+3)(x+5)=0

Therefore the roots of the equation are -3,-5

Answer 2

EXPLANATION.

Roots of the quadratic equation.

⇒ x² + 8x + 15.

As we know that,

Factorizes the equation into middle term splits, we get.

⇒ x² + 5x + 3x + 15 = 0.

⇒ x(x + 5) + 3(x + 5) = 0.

⇒ (x + 3)(x + 5) = 0.

⇒ x = - 3 and x = - 5.

Option [C] is correct answer.

                                                                                                                       

MORE INFORMATION.

Conjugate roots.

(1) = If D < 0.

One roots = α + iβ.

Other roots = α - iβ.

(2) = If D > 0.

One roots = α + √β.

Other roots = α - √β.