SOLUTION: Two ladders lean against opposite walls in a 10-foot wide alley. One ladder reaches 30 feet up the wall; the other reaches 20 feet up the wall. The foot of each ladder is at the

Algebra ->  Equations -> SOLUTION: Two ladders lean against opposite walls in a 10-foot wide alley. One ladder reaches 30 feet up the wall; the other reaches 20 feet up the wall. The foot of each ladder is at the       Log On


   



Question 306424: Two ladders lean against opposite walls in a 10-foot wide alley. One ladder reaches 30 feet up the wall; the other reaches 20 feet up the wall. The foot of each ladder is at the base of the opposite wall. How high above the ground do the ladders cross?
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Let the first ladder be the 30' ladder.
The base is (0,0), then end at (10,30).
The equation that describes this ladder is
y=3x
The second ladder's base is (10,0) and the end is at (0,20).
The equation that describes this ladder is
y=20-2x
Find the intersection point.
3x=20-2x
5x=20
x=4
When x=4, then
y=3x=3%284%29=12
They intersect 12' above the ground.