Answer
$48$ pounds per square inch pressure is needed to reach a fire $50$ feet away.
Work Step by Step
The given formula is
$\Rightarrow d=\frac{1}{2}n+26$
Substitute $50$ for $d$.
$\Rightarrow 50=\frac{1}{2}n+26$
Subtract $26$ from each side.
$\Rightarrow 50-26=\frac{1}{2}n+26-26$
Simplify.
$\Rightarrow 24=\frac{1}{2}n$
Multiply each side by $2$.
$\Rightarrow 2\cdot 24=2\cdot \frac{1}{2}n$
Simplify.
$\Rightarrow 48=n$
Hence, $48$ pounds per square inch pressure is needed to reach a fire $50$ feet away.
