11) \( x-15=20 \)

To solve the equation \( x - 15 = 20 \), you simply need to isolate the variable \( x \). Start by adding 15 to both sides of the equation. This gives you \( x = 20 + 15 \), which simplifies to \( x = 35 \). Easy peasy! Now, here’s a quick check: if you substitute \( x = 35 \) back into the original equation, \( 35 - 15 \) equals 20. You’ve got it right! Always remember, checking your work is a great way to confirm your answers.