Q. Express the following fraction in simplest form, only using positive exponents.−20r−35(r4)3Answer:
Identify negative exponent: Write down the given expression and identify the negative exponent.The given expression is (5(r4)3)/(−20r−3).We have a negative exponent in the denominator which is r−3.
Apply power of power rule: Apply the power of a power rule to the numerator.The power of a power rule states that (am)n=am∗n.So, (r4)3=r4∗3=r12.Now the expression becomes (5r12)/(−20r−3).
Convert negative exponent: Convert the negative exponent to a positive exponent by moving the term to the numerator.According to the exponent rules, a−n=an1 when moving from the denominator to the numerator.So, r−3 becomes r3 when moved to the numerator.Now the expression becomes (5r12⋅r3)/(−20).
Combine like terms: Combine the like terms in the numerator using the product of powers rule.The product of powers rule states that am×an=am+n.So, r12×r3=r12+3=r15.Now the expression becomes (5r15)/(−20).
Simplify fraction: Simplify the fraction by dividing both the numerator and the denominator by their greatest common divisor.The greatest common divisor of 5 and 20 is 5.Divide both the numerator and the denominator by 5.55r15/5−20 = r15/(−4).
Make denominator positive: Since we cannot have a negative in the denominator, we can multiply the numerator and the denominator by −1 to make the denominator positive.Multiplying by −1, we get (−1×r15)/(−1×−4)=−r15/4.
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