Answer
$t\leq-6$ and $t\geq1$
Work Step by Step
Step 1: Inequality is already factorized, so the roots of the function is $t=-6$ and $t=1$
Step 2: Distribute brackets $t^2+5t-6$.
Step 3: The function is positive and equal to $0$ where $t\leq-6$ and $t\geq1$
