How do you factor #49x^2 + 64y^2 #?
1 Answer
Nov 15, 2015
Explanation:
This quadratic has no linear factors with Real coefficients, but it can be treated as a difference of squares using pure imaginary coefficients,
The difference of squares identity can be written:
#a^2-b^2 = (a-b)(a+b)#
Use this with
#49x^2 + 64y^2 = (7x)^2 + (8y)^2 = (7x)^2 - (8iy)^2#
#= (7x-8iy)(7x+8iy)#
