Answer
$z\lt13$
Work Step by Step
$6z-15\lt4z+11$ $\longrightarrow$ add 15 to both sides; subtract 4z from both sides
$6z-15+15-4z\lt4z+11+15-4z$ $\longrightarrow$combine like terms
$2z\lt26$ $\longrightarrow$ divide both sides by 2
$2z\div2\lt26\div 2$ $\longrightarrow$ simplify
$z\lt13$
