algebra 2 help plz...? w/ question?

Question

A landscaper is designing a flower garden in the shape of a trapezoid. She wants the shorter base to be 3 yards greater than the height and the longer base to be 7 yards greater than the height. She wants the area to be 210 square yards. The situation is modeled by the equation h^2 + 5h = 210. Use the Quadratic Formula to find the height that will give the desired area. Round to the nearest hundredth of a yard.

a.
24.41 yards

b.
430 yards

c.
14.71 yards

d.
12.21 yards

Answer 1

the quadratic equation states that the solution to a quadratic function is:

[-b +/- sqrt(b^2 - 4*a*c)]/2*a

when the quadratic function is in the form of

a*x^2 + b*x + c = 0

For your example we must first put it into this form by moving all the terms to one side:

h^2 + 5*h - 210 = 0

now a = 1, b = 5, and c = -210

so:

h = [-5 + sqrt{5^2 - 4*1*(-210)}]/2*1 = 12.21 or
h = [-5 - sqrt{5^2 - 4*1*(-210)}]/2*1 = -17.21

since the height cannot be below zero, we can rule out -17.21 and select 12.21. The answer is d.

Answer 2

you can cancel out b and a, they're too far apart.. though i didnt read the question.

Answer 3

14.71