KL = 23
so you just have to add both of the segment lengths together.
each individual equation is already given in the image, so I'll substitute it out below:
JK + KL = JL
4x+2 +4x+3 = 45
8x + 5 = 45
8x = 40
x = 5
BUT WE'RE NOT DONE. plug in 40 for the variable X:
KL = 4(5) + 3
KL = 20 + 3
KL = 23
now i'll check my answer really quickly:
23 + 4(5) + 2 = JL
23 + 20 + 2 = JL
23 + 22 =
45
therefore, KL is 23