Question

Please help me with this math question. Thank you.

Answer 1

Answer:

D

Step-by-step explanation:

We want to find the values of x such that:

$\displaystyle -x^2 + 7x + 5 = 0$

We can use the quadratic formula. Recall that:
$\displaystyle x = \frac{-b\pm\sqrt{b^2-4ac}}{2a}$

In this case, a = -1, b = 7, and c = 5. Substitute and evaluate:
$\displaystyle \begin{aligned} x & = \frac{-(7)\pm\sqrt{(7)^2-4(-1)(5)}}{2(-1)}\\ \\ & = \frac{-7\pm\sqrt{49+20}}{-2} \\ \\ & = \frac{-7\pm\sqrt{69}}{-2}\end{aligned}$

In conclusion, the answer is D.

Answer 2

$x²+7x + 5=0$

Quadratic formula is

$x = \frac{- b ± \sqrt{b² - 4ac}}{2a}$

Values given $a = 1, b = 7, c = 5$

$x = \frac{-(-7) ± \sqrt{(-7)² - 4 × 1 × (-5)}}{2 × (-1)}$

$x =\frac{7 ± \sqrt{49 + 20}}{-2}$

$x =\frac{7 ± \sqrt{69}}{-2}$

${\boxed{{x =\frac{7 ± \sqrt{69}}{-2} }}} \: is \: answer$