A 25 foot ladder leans against a house. How far is the foot of the ladder from base of the building
if the top of the ladder is 20 feet from the ground?
A. 20 ft
B. 15 ft
C. 18 ft
D. 10 ft

the answer will be the last one

let's call the solutions x₁ = (5 - 2√7)/3 and x₂ = (5 + 2√7)/3

then the equation is (x-x₁)(x-x₂) = 0

if you fill that in you get a lot of numbers which you can recognize as ax²+bx+c=0.

step-by-step explanation:

you can see that a=1 (there is just an x²)

b = (-5 -2√7 + 2√7 - 5)/3 = -10/3

c = -2√7)/3 ) * (-5+2√7)/3) = -1/3

so your answer is 3x^2 – 10x – 1 = 0

x:       y:  

-1         4

0         4

1         6

2         18

3         20