LM=1/2z+2 MN=3z+3/2 LN=5z+2
Use LM+MN=LN
(1/2z+2)+(3z+3/2)=5z+2
3.5z+3.5=5z+2 (combine like terms)
1.5=1.5z (move Zs to right, #s to left)
1=z (divide by 1.5)
To check the answer,
LM=1/2(1)+2 MN=3(1)+3/2 LN=5(1)+2
LM=1/2+2 MN=3+(3/2) LN=5+2
LM=2.5 MN=4.5 LN=7
2.5+4.5=7, so true