[tex]7x-27=4x+12[/tex]
To solve for x, we need to join similar terms on either side. For this, we'll transfer 4x to the left side and -27 to the right side. When transferring terms, their sign will reverse as well. From positive to negative and negative to positive. See below.
[tex]\begin{gathered} 7x-4x=12+27 \\ 3x=39 \\ \text{Divide both sides by 3.} \\ \frac{3x}{3}=\frac{39}{3} \\ x=13 \end{gathered}[/tex]The value of x that makes the equation true is 13.
To check that, substitute the x-value with 13.
7x - 27 = 4x + 12
7(13) - 27 = 4(13) + 12
91 - 27 = 52 + 12
64 = 64
