Can someone help me with geometry please? ?

Question

I was absent on the day we learned this in class, im trying to do the homework for it and im extremely confused.

suppose M is between L and N. use the segment addition postulate to solve for the variable. then find the lengths of LM, MN, and LN.

LM = 3x + 8

MN = 2x - 5

LN = 23

if someone could explain how to do this i would really appreciate it =)

Answer 1

LM+MN=LN

then u plug in the numbers

3x+8+2x-5 = 23

solve for x

5x+3=23

substract 3 from both side and u will get

5x=20

x=20/5=4

x=4

to find the length on LM,MN just plug in the x=4 into their equation

Answer 2

add LM and MN   and it gives you this  5x+3=23

x=4

then plug in x for equations. and 3(4)+8= 20   LM

and MN  2 (4) -5=3

thus LN=LM=MN  :D