Given the expression:
[tex]27=45+9a[/tex]to solve for a, we have to move every term and coefficient to the other side. First we move the 45 to the other side with a negative sign (since it is adding to 9a) and then we move the 9 to the other side dividing, since it is multiplying a. Then we get the following:
[tex]\begin{gathered} 27=45+9a \\ \Rightarrow27─45=9a \\ \Rightarrow9a=─18 \\ \Rightarrow a=\frac{─18}{9}=─2 \\ a=─2 \end{gathered}[/tex]therefore, a=-2
