The mistake which Carlos made was subtracting 2x from the left-hand side of the equation, instead of adding 2x to 3x.
In order to evaluate and solve this equation, we would have to apply the PEMDAS rule, where mathematical operations within the parenthesis (grouping symbols) are first of all evaluated, followed by exponent, and then multiplication or division from the left side of the equation to the right.
Lastly, the mathematical operations of addition or subtraction would be performed from left to right.
Based on the information provided, we solve the following mathematical equation by taking the square of both sides of the equation:
3x + 2x - 6 = 24
By adding 2x and 3x together, we have;
5x - 6 = 24
By adding 6 to both sides of the equation, we have:
5x - 6 + 6 = 24 + 6
5x = 30
x = 30/5
x = 6