Question

Which are the solutions of the quadratic equation?

Answer 1

Answer: the answer is C.

Step-by-step explanation:got it right

Answer 2

Answer:

$x_1=\frac{7+\sqrt{65}} {2}$

$x_2=\frac{7-\sqrt{65}} {2}$

Step-by-step explanation:

we know that

The formula to solve a quadratic equation of the form

$ax^{2} +bx+c=0$

is equal to

$x=\frac{-b\pm\sqrt{b^{2}-4ac}} {2a}$

in this problem we have

$x^{2}=7x+4$  

equate to zero

$x^{2}-7x-4=0$  

so

$a=1\\b=-7\\c=-4$

substitute in the formula

$x=\frac{-(-7)\pm\sqrt{-7^{2}-4(1)(-4)}} {2(1)}$

$x=\frac{7\pm\sqrt{65}} {2}$

therefore

$x_1=\frac{7+\sqrt{65}} {2}$

$x_2=\frac{7-\sqrt{65}} {2}$

StartFraction 7 minus StartRoot 65 EndRoot Over 2 EndFraction comma StartFraction 7 + StartRoot 65 EndRoot Over 2 EndFraction