Is -(-49) equal to -49?

Tracy solved the following problem. which of the statements is true? 9 ÷ 3 + 6 × 2 3 + 6 × 2 9 × 2 18 her answer is correct. her answer is incorrect. she should have multiplied before dividing. her answer is incorrect. she should have multiplied before adding. her answer is incorrect. she should have added before dividing.

In simplified exponential notation, the expression a^2•a^-3•a 1/a 0

He concluded that a heavier object dropped from the same height as a lighter object will land