Same thing as we did in 41.
Add 2 to both sides, to get, \(|2x+1|\geq7\)
|f(x)| greater than or equal to a, f(x) less than or equal to a, or f(x) greater than or equal to a
\(2x+1\leq-7: x\leq-4\)
\(2x+1\geq7: x\geq3\)
Combine the ranges, to get \(x\leq-4 \) or \(x\geq3\)