Discover how IDNLearn.com can help you find the answers you need quickly and easily. Our community provides accurate and timely answers to help you understand and solve any issue.

The Fraction Raised to a Negative Exponent Rule

When you have a fraction raised to a negative exponent, you can simply replace it with the reciprocal of the fraction raised to a positive exponent.

[tex] \left(\frac{a}{b}\right)^{-n}=\left(\frac{b}{a}\right)^n [/tex]

Simplify the following:

[tex] \left(\frac{2}{5}\right)^{-2} = \square [/tex]

Simplify:

[tex] \left(\frac{x^3}{7}\right)^{-3} = \square [/tex]


Sagot :

Certainly! Let's simplify the given expressions step-by-step using the reciprocal rule for negative exponents.

Expression 1:
[tex]\[ \left(\frac{2}{5}\right)^{-2} \][/tex]

Step 1: Apply the reciprocal rule, which states that [tex]\(\left(\frac{a}{b}\right)^{-n} = \left(\frac{b}{a}\right)^n\)[/tex].

[tex]\[ \left(\frac{2}{5}\right)^{-2} = \left(\frac{5}{2}\right)^2 \][/tex]

Step 2: Raise the fraction [tex]\(\left(\frac{5}{2}\right)\)[/tex] to the power of [tex]\(2\)[/tex].

[tex]\[ \left(\frac{5}{2}\right)^2 = \frac{5^2}{2^2} = \frac{25}{4} = 6.25 \][/tex]

So, the simplified form of [tex]\(\left(\frac{2}{5}\right)^{-2}\)[/tex] is:

[tex]\[ 6.25 \][/tex]

Expression 2:
[tex]\[ \left(\frac{x^3}{7}\right)^{-3} \][/tex]

Step 1: Apply the reciprocal rule, which states that [tex]\(\left(\frac{a}{b}\right)^{-n} = \left(\frac{b}{a}\right)^n\)[/tex].

[tex]\[ \left(\frac{x^3}{7}\right)^{-3} = \left(\frac{7}{x^3}\right)^3 \][/tex]

Step 2: Raise the fraction [tex]\(\left(\frac{7}{x^3}\right)\)[/tex] to the power of [tex]\(3\)[/tex].

[tex]\[ \left(\frac{7}{x^3}\right)^3 = \frac{7^3}{(x^3)^3} = \frac{343}{x^9} \][/tex]

So, the simplified form of [tex]\(\left(\frac{x^3}{7}\right)^{-3}\)[/tex] is:

[tex]\[ \frac{343}{x^9} \][/tex]

Thus, the final simplified answers are:

[tex]\[ \left(\frac{2}{5}\right)^{-2} = 6.25 \][/tex]
[tex]\[ \left(\frac{x^3}{7}\right)^{-3} = \frac{343}{x^9} \][/tex]