Question

Find the sum of the roots of the quadratic x^2 + 7x - 13 = 0

Answer 1

Answer:

-7

Step-by-step explanation:

You use the quadratic formula of $ax^{2} +bx+c = 0$ to get:

a = 1

b = 7

c = -13

then you plug that into x= (-b ± √b²-4ac)/(2a) :

x= ( -7 ± √7²- 4(1)(-13) )/(2(1))

$x=-\frac{7}{2} + \frac{\sqrt{101}}{2} \\\\x=-\frac{7}{2} - \frac{\sqrt{101}}{2}$

The sum of these two x values turns out to be:

$x=-\frac{7}{2} + \frac{\sqrt{101}}{2}+( -\frac{7}{2} - \frac{\sqrt{101}}{2} )= -\frac{14}{2} = 7$