(1/6x-4y )+ (1/6x-4y )+ (4y/4y^2-9x^2)
=2/(6x-4y)+4y/(2y+3x)(2y-3x)
=2(2y+3x)/2(2y+3x)(2y-3x)+8y/2(2y+3x)(2y-3x)
=(4y+6x+8y)/2(2y+3x)(2y-3x)
=6(x+2y)/2(2y+3x)(2y-3x)
=3(x+2y)/(2y+3x)(2y-3x)
(1/6x-4y )+ (1/6x-4y )+ (4y/4y^2-9x^2)
=2/(6x-4y)+4y/(2y+3x)(2y-3x)
=2(2y+3x)/2(2y+3x)(2y-3x)+8y/2(2y+3x)(2y-3x)
=(4y+6x+8y)/2(2y+3x)(2y-3x)
=6(x+2y)/2(2y+3x)(2y-3x)
=3(x+2y)/(2y+3x)(2y-3x)