Question

For each pair of similar triangles, find the value of x.

Image:
http://i.imgur.com/dQ9jXVd.jpg

Answer 1

Given 2 similar triangle
=>39/(x+6) = (2x-4)/24
=>39*24=(x+6)(2x-4)
=>936=2x^2+8x-24
=>2x^2+8x-960=0
by solving this quadratic equation
=>x=-24 and x=20
neglecting x=-24
hence x=20 is the answer

CBSE sample papers for class 10 2013 http://goo.gl/yRzgKk