Question

Solve. -5x^2+9+7x = 0−5x 2 +9+7x=0

Answer 1

Answer:

x =$\frac{-7 \frac{+}{} \sqrt{229} }{-10}$, or x=2.21327 and -0.81327

Step-by-step explanation:

$-5x^2+7x+9 = 0$

see if equation is factor-able:

$\left[\begin{array}{ccc}?&9\\-5x^2&?\\\end{array}\right]$

the two ? must multiply together to $-45x^2$ and add up to 7x

no two integers times x can solve, so we must use quadratic equation

$x = \frac{-b \frac{+}{} \sqrt{b^2-4ac} }{2a}$, given a quadratic $ax^2 +bx +c$

so

$x = \frac{-7 \frac{+}{} \sqrt{49+180} }{-10} = \frac{-7 \frac{+}{} \sqrt{229} }{-10}$