Chapter 2 - Functions, Equations, and Graphs - 2-4 More About Linear Equations - Practice and Problem-Solving Exercises - Page 86: 25

$42x-10y=-79$

Using the properties of equality, in the form $Ax+By=C$ or the Standard Form of Linear Equations, the given equation, is equivalent to: \begin{align*} -4.2x+y&=7.9 \\\\ -10(-4.2x+y)&=(7.9)(-10) \\\\ 42x-10y&=-79 \end{align*}