Simplifying exponential expressions

In summary, the given expression is simplified by expanding the brackets and combining like terms, resulting in the answer of 1/2p^2. The error in the calculation was due to flipping the 8 to the denominator, which cannot be done since it does not have a negative exponent. Leaving the 8 in the numerator would have led to the correct solution. It is important to carefully follow the rules of simplifying expressions with exponents to avoid errors.
  • #1
arl2267
15
0
Simplify 8p-3 x (4p2)-2/p-5.

This is what I got:

First thing I did was flip everything to get rid of the negative exponents:

p5/8p3x(4p2)2

next thing I did was multiply the 4p2 by 2

p5/ 8p3x16p4Then I subtracted thep5 from the 8p3

p2/8x16p4

and ended up with

1/128p2 I know that the answer is 1/2p2​ so where did I go wrong?
 
Last edited by a moderator:
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  • #2
After expanding the brackets

$\displaystyle \frac{8p^{-3}\times 4^{-2}\times p^{-4}}{p^{-5}}$

$\displaystyle \frac{8p^{-3}\times p^{-4}}{4^{2}\times p^{-5}}$

You can now see the numerical part is $\displaystyle\frac{8}{16}= \frac{1}{2}$
 
  • #3
In your first step where you "flip" everything, you cannot do this with the 8 since it does not have a negative exponent. If you had left the 8 in the numerator, then you would have gotten the desired result.

edit: Welcome to the forum, and I certainly appreciate the fact that you show your work...this makes it much easier to address where your error(s) may be.:cool:
 

Related to Simplifying exponential expressions

What is an exponential expression?

An exponential expression is a mathematical expression that contains a base number and an exponent. The exponent indicates how many times the base number is multiplied by itself.

Why is it important to simplify exponential expressions?

Simplifying exponential expressions makes them easier to work with and understand. It also allows for the use of mathematical rules and properties to solve problems involving these expressions.

What are the basic rules for simplifying exponential expressions?

The basic rules for simplifying exponential expressions include multiplying exponents with the same base, dividing exponents with the same base, and raising a power to a power.

How do you simplify exponential expressions with negative exponents?

To simplify exponential expressions with negative exponents, you can rewrite the expression by moving the term with the negative exponent to the denominator and changing the sign of the exponent to positive.

What are some real-life applications of simplifying exponential expressions?

Simplifying exponential expressions is used in various fields such as finance, biology, and physics. For example, in finance, exponential growth and decay can be modeled using exponential expressions. In biology, exponential functions are used to model population growth. In physics, exponential decay is used to model radioactive substances.

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