Take a closer look at the first step. Are the expressions on the right-hand side equivalent?
Error: See solution. Solution: x=10+3b/a
Practice makes perfect
Let's take a look at the first step in the given solution.
In the attempted solution an x was factored out — this is the error. The variable could not have been factored out from both terms, since the second term does not involve x. Let's distribute x in the second expression to see that the expressions on the right-hand side are not equivalent.
We see that what we got is not the same as what we started with in the first line.
ax-3xb ≠ax -3b
Instead, we should solve for x by first adding 3b to both sides of the equation.
