Answer:
D. 13
Step-by-step explanation:
well since it's a quadratic equation, it can be written in the form of ax²+bx+c=0. So we have a=1, b=b and c= -30. Also the roots are given by the equation-
x= -b± /2a. So all I did was put the number from the choices which would satisfy the sqrt part and that turned out to be 13 since
=
= 17. So b=13.
Let us assume base of the window = b feet.
Height is 3 feet less than base, that is = (b-3).
Given area of the triangle = 20 feet square.
We know formula for area of a triangle:
Area = × Base × Height
Plugging values in formula, we get
20 =
Factoring quadratic, we get
=0
b+5=0
b=-5
b-8=0
b=8.
For base we can take only positive value.
<h3>Therefore, base of the triangle = 8 feet and height = 8 -3 = 5 feet.</h3>