Prove that the following triplets of the lines are concurrent. x+2y=0,3x-4y-10=0,5x+3y-7=0
2x-7y+10=0,3x-2y=0,x-12y+21=0
9x-13y-90=0,2x+11y-20=0,7x+y-70=0

set each factor equal to 0

4x-3 = 0

2x-1 = 0

solve for x.

4x-3=0

4x=3

x= 3/4

solve for x. 

2x-1= 0

2x= 1

x= 1/2

eventually after a few more steps, your answer should be 1/2 is less than or equal to x and 3/4 is greater than or equal to x

translate k to n and reflect across the line containing jk.