91Ó°ÊÓ

Simplify${(2m−3n)}^2$ .

Express the number$\mathbf{0}\mathbf{.}\mathbf{000862}$ in scientific notation.

Evaluate$(3.42×{10}^8)(1.1×{10}^{−5})$ . Express the result in scientific notation.

Find the area of the triangle shown.

Evaluate$\frac{8×{10}^{−1}}{16×{10}^{−2}}$ . Express the result in scientific notation.

Determine whether the expression$3z^2−5z+11$ is a polynomial. If it is a polynomial state the degree of the polynomial.

Refer to Example 7 on page 225. The average distance from Earth to the Moon is about$3.84×{10}^8$ meters. How long would it take a radio signal traveling at the speed of light to cover that distance?

Simplify$a^2â‹\dots a^6$ assuming that no variable equal to0.

Simplify$b^{−3}â‹\dots b^7$ assuming that no variable equal to 0 .

Determine whether$x^yâ‹\dots x^z=x^{yz}$ , is sometimes, always or never true. Explain.