Beginning Algebra With Applications, Chapter 5, 5.2, Section 5.2, Problem 106

Graph $3x+4y =12$ by using $x$- and $y$-intercepts

$x$-intercept:


$\begin{equation} \begin{aligned} 3x+4y =& 12 && \text{Given equation} \\ 3x + 4(0) =& 12 && \text{To find the $x$-intercept, let } y = 0 \\ 3x =& 12 && \text{Divide by } 3 \\ x =& 4 && \end{aligned} \end{equation}$


The $x$-intercept is $(4,0)$

$y$-intercept:


$\begin{equation} \begin{aligned} 3x+4y =& 12 && \text{Given equation} \\ 3(0) + 4y =& 12 && \text{To find the $y$-intercept, let } x=0 \\ 4y =& 12 && \text{Divide by } 4 \\ y =& 3 && \end{aligned} \end{equation}$



The $y$-intercept is $(0,3)$

Graph the ordered pairs $(4,0)$ and $(0,3)$. Draw a straight line through the points.