## Geometry: Common Core (15th Edition)

$\overline{JK}+\overline{KL}=\overline{JL}\longrightarrow$ Segment Addition Postulate $(4x+6)+(7x+15)=120\longrightarrow$ Substitute $11x+21=120\longrightarrow$ Combine like terms $11x+21-21=120-21$ Subtract 21 from each side $11x=99\longrightarrow$ Simplify $11x\div11=99\div11\longrightarrow$ Divide each side by 11 $x=9$ Substitute to find the lengths of each segment. JK is $4x+6=4(9)+6=36+6=42$ KL is $7x+15=7(9)+15=63+15=78$