Raymond B. answered 07/19/21
Math, microeconomics or criminal justice
y = -x^2 -4x + 7, set = zero and multiply by -1
x^2 +4x -7 =0
x^2 +4x = 7 complete the square or use the quadratic formula, if it doesn't factor
= x^2 +4x + 4 = 7 +4 take half the x coefficient and square it, then add 4 to both sides
(x+2)^2 = 11 take square roots of both sides
x+2 =+ or - sqr11 subtract 2 from both sides
x= -2 + or - sqr11 = about 1,3 or - 5.3 square root of 11 is about 3.3
if you graph the equation, it will intersect the x axis at about (1.3, 0) and (-5.3, 0)
It's a downward opening parabola with axis of symmetry x=-2
vertex and maximum point (-2, 11)
y intercept (0,7)
x intercepts about (1.3, 0) and (-5.3, 0)
IF you graphed it, where the curve intersects the x axis are the two solutions to the equation.