Answer
All real numbers
Work Step by Step
$8z+5-2z\leq3(2z+1)+2\longrightarrow$ multiply using the distributive property
$8z+5-2z\leq6z+3+2\longrightarrow$ combine like terms
$6z+5\leq6z+5$
Since the two expressions are equivalent, the inequality will always be true for any real number value of z.
