State the name of the property illustrated. 6+(2+7)=(6+2)+7

Determine whether each statement is true or false. {3, 5, 9, 10} ∪ ∅ = {3, 5, 9, 10}

Add or subtract as indicated. Write answers in lowest terms as needed. $7\frac{5}{12}-4\frac{5}{6}$

Write each number in decimal notation without the use of exponents. $-7.00001\times {10}^{10}$

Determine whether each statement is true or false. {1, 2, 4} ∪ {1, 2, 4} = {1, 2, 4}

Find each product or quotient where possible. $\frac{\frac{12}{13}}{-\frac{4}{3}}$

In Exercises 77–86, write each number in scientific notation. 64,000

Find each product or quotient where possible. $\frac{\frac{7}{6}}{-\frac{2}{3}}$

Determine whether each statement is true or false. ∅ ∪ ∅ = ∅