Solve the following exercise:
Solve the following exercise:
To open the parentheses on the left side, we'll use the formula:
We'll arrange the equation so that the terms with 'a' are on the right side, and maintain the plus and minus signs during the transfer:
Let's group the terms on the right side:
Let's divide both sides by 39:
Note that we can reduce the fraction since both numerator and denominator are divisible by 3: