Answer:
(x+4)(x+5) = 0
Explanation:
The standard form of the quadratic equation is:
ax² + bx + c = 0
The given equation is:
x² + 20 = -9x
Adding 9x to both sides would make us reach the standard form which would be:
x² + 9x + 20 = 0
By comparison:
a = 1
b = 9
c = 20
To factor the equation, we would need to use the quadratic formula shown in the attached image.
By substitution, we ould find that:
either x = [tex] \frac{-9+ \sqrt{(9)^2-4(1)(20)} }{2(1)} = -4[/tex]
This means that the first factor is (x+4)
or x = [tex] \frac{-9+ \sqrt{(9)^2-4(1)(20)} }{2(1)} = -5[/tex]
This means that the second factor is (x+5)
Based on the above, the factored form of the equation would be:
(x+4)(x+5) = 0
Hope this helps :)