Question

Select the two values of x that are roots of this equation. 2x+11x+15= 0

Answer 1

Answer:

The roots of the equation are x=-3 and x=-2.5

Step-by-step explanation:

The correct quadratic equation is

2x^2+11x+15=0

we know that

The formula to solve a quadratic equation of the form

$ax^{2} +bx+c=0$ is equal to

$x=\frac{-b(+/-)\sqrt{b^{2}-4ac}} {2a}$

in this problem we have

$2x^{2} +11x+15=0$  

so

$a=2\\b=11\\c=15$

substitute in the formula

$x=\frac{-11(+/-)\sqrt{11^{2}-4(2)(15)}} {2(2)}$

$x=\frac{-11(+/-)\sqrt{121-120}} {4}$

$x=\frac{-11(+/-)\sqrt{1}} {4}$

$x=\frac{-11(+/-)1} {4}$

$x_1=\frac{-11(+)1}{4}=-2.5$

$x_2=\frac{-11(-)1}{4}=-3$

therefore

The roots of the equation are x=-3 and x=-2.5