Step-by-step explanation:
2x + 7 = 27 OR 3 + 3x = 30.
2x = 27 - 7 OR 3x = 30 - 3
2x = 20 OR 3x = 27
x = 20/2 OR x = 27/3
x = 10 OR x = 9
<span>To do that, you need to set it all to zero and factor:
x^2+8x+15 = 0
(x+5)(x+3) = 0
then put both those in parentheses chunks in their own equations
x + 5 = 0
x + 3 = 0
and then simplify
x = -5
x = -3
So the two points where the parabola crosses the x-axis are -5 and -3.</span>
X^2 = 16
x = 4
x = -4
good luck :)