Intermediate Algebra, Chapter 1, 1.3, Section 1.3, Problem 92

Evaluate the expression $\displaystyle w - 6x + 5y - 3z$ for $w = 4, x = - \frac{3}{4}, y = \frac{1}{2}$ and $z = 1.25$.


$
\begin{equation}
\begin{aligned}

w - 6x + 5y - 3z =& 4 - 6 \left( - \frac{3}{4} \right) + 5 \left( \frac{1}{2} \right) - 3 (1.25)
&& \text{Substitute } w = 4, x = - \frac{3}{4}, y = \frac{1}{2} \text{ and } z = 1.25
\\
\\
=& 4 + \frac{9}{2} + 5 \left( \frac{1}{2} \right) - 3 (1.25)
&& \text{Multiply}
\\
\\
=& 4 + \frac{9}{2} + \frac{5}{2} - 3 (1.25)
&& \text{Multiply}
\\
\\
=& 4 + \frac{9}{2} + \frac{5}{2} - \frac{15}{4}
&& \text{Multiply}
\\
\\
=& \frac{16}{4} + \frac{18}{4} + \frac{10}{4} - \frac{15}{4}
&& \text{Get the LCD}
\\
\\
=& \frac{34}{4} + \frac{10}{4} - \frac{15}{4}
&& \text{Add}
\\
\\
=& \frac{44}{4} - \frac{15}{4}
&& \text{Add}
\\
\\
=& \frac{29}{4}
&& \text{Subtract}

\end{aligned}
\end{equation}
$