Chapter 2 - Functions, Equations, and Graphs - 2-2 Direct Variation - Practice and Problem-Solving Exercises - Page 73: 61

$x=-5$

We start by distributing and simplifying. We have $4(x-5)+x=8x-10-x$ is $4x-20+x=8x-10-x$. Simplifying gives us $5x-20=7x-10$. Now we want to put x with its coefficient on one side of the equation and the other numbers on the other side. We can do this by adding $-7x$ and $20$ to both sides. That gives us $-2x=10$. Now, we want to fully isolate x so we divide both sides by -2, so $x=-5$.