How do you evaluate the expression for $8 \cdot 3^{x}$ $8*3^x$ if $x = - 2$ $x=-2$ and if $x = 3$ $x=3$ ?

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Answer 1 · 2017-01-06T12:52:55

See full explanation below.

For each of these you Substitute the value for $x$ $x$ in the expression.

Problem 1: Solve for $x = - 2$ $x = -2$

$8 \cdot 3^{- 2}$ $8 * 3^(-2)$

We can use this rule for exponents to rewrite this problem:

$x^{a} = \frac{1}{x^{- a}}$ $x^color(red)(a) = 1/x^color(red)(-a)$

$8 \cdot \frac{1}{3^{(- - 2)}}$ $8*1/3^color(red)((- -2))$

$8 \cdot \frac{1}{3^{2}}$ $8*1/3^color(red)(2)$

$8 \cdot \frac{1}{9}$ $8*1/9$

$\frac{8}{9}$ $8/9$

Problem 1: Solve for $x = 3$ $x = 3$

$8 \cdot 3^{3}$ $8 * 3^3$

$8 \cdot 27$ $8*27$

$216$ $216$

How do you evaluate the expression for 8⋅3x8*3^x if x=−2x=-2 and if x=3x=3?