11. Insert parentheses to make the equation true. \( 15 \times 2^{2}-4+12 \div 2=50 \)

To make the equation \( 15 \times 2^{2} - 4 + 12 \div 2 = 50 \) true by inserting parentheses, we can try the following arrangement: \( 15 \times (2^{2} - 4) + (12 \div 2) = 50 \). Breaking it down, we calculate inside the parentheses first: - \( 2^{2} = 4 \), - \( 4 - 4 = 0 \), - So, \( 15 \times 0 = 0 \), - \( 12 \div 2 = 6 \), - Finally, \( 0 + 6 = 6 \), which does not equal 50. It seems this doesn't work. Let’s try another approach: The correct parentheses arrangement is \( 15 \times 2^{2} - (4 + 12 \div 2) = 50 \). Calculating inside the parentheses first: - \( 12 \div 2 = 6 \), - So, \( 4 + 6 = 10 \), - Now substitute back: \( 15 \times 4 = 60 \), - Finally, \( 60 - 10 = 50 \), which is correct! So, the expression is true with the parentheses as follows: \( 15 \times 2^{2} - (4 + 12 \div 2) = 50 \).