How do you solve 13-4x < 25?

Jul 24, 2018

$x > - 3$

Explanation:

$13 - 4 x < 25$

Add $\textcolor{b l u e}{4 x}$ to both sides:
$13 - 4 x \quad \textcolor{b l u e}{+ \quad 4 x} < 25 \quad \textcolor{b l u e}{+ \quad 4 x}$

$13 < 25 + 4 x$

Subtract $\textcolor{b l u e}{25}$ from both sides:
$13 \quad \textcolor{b l u e}{- \quad 25} < 25 + 4 x \quad \textcolor{b l u e}{- \quad 25}$

$- 12 < 4 x$

Divide both sides by $\textcolor{b l u e}{4}$:
$\frac{- 12}{\textcolor{b l u e}{4}} < \frac{4 x}{\textcolor{b l u e}{4}}$

$- 3 < x$

Therefore,
$x > - 3$

Here's a graph of it on a number line:

The open circle on $- 3$ means that it is not a solution (but anything greater than it is).

Hope this helps!