Posted by Kate on .
The top of a 15foot ladder is 3 ft. father up a wall than the foot of the ladder is from the bottom of the wall. How far is the foot of the ladder from the bottom of the wall?

math 
drwls,
Let x be the distance of the foot from the wall. Then use the Pythagorean theorem.
x^2 + (x+3)^2 = 15^2 = 225
2x^2 +6x 216 = 0
x^2 +3x 108 = 0
That factors easily. (Think: 9x12 = 108)Take the positive root.