Ontario Mathematics Proficiency Practice Test

To solve the equation \(2x + 5 = 15\), the goal is to isolate \(x\).

First, you start with the original equation:

\[ 2x + 5 = 15 \]

Next, you can eliminate the constant on the left side by subtracting 5 from both sides of the equation:

\[ 2x + 5 - 5 = 15 - 5 \]

This simplifies to:

\[ 2x = 10 \]

Now, to isolate \(x\), you need to divide both sides by 2:

\[ \frac{2x}{2} = \frac{10}{2} \]

This results in:

\[ x = 5 \]

Thus, the solution to the equation is \(x = 5\).

This is why the correct answer reflects that value, confirming that solving the equation step-by-step leads to the correct isolation of \(x\). Adding or subtracting constants and dividing coefficients accurately is key in solving linear equations like this one.