1. ## Subtracting Mixed Numbers

Does anybody know how to do this without using square roots? I am terrible at square roots and they confuse me but anyway I've see to solve it involves square roots.

2. ## Re: Subtracting Mixed Numbers

$2^{5/2} - 2^{3/2}= 2(2^{3/2})-2^{3/2} = (2-1)2^{3/2} = 2^{3/2}$

3. ## Re: Subtracting Mixed Numbers

Originally Posted by whytbh
Does anybody know how to do this without using square roots? I am terrible at square roots and they confuse me but anyway I've see to solve it involves square roots.
$\Large{2^{\frac{5}{2}}-2^{\frac{3}{2}}}=2^{\frac{3}{2}}\left(2^{\frac{2}{ 2}}-1\right)=?$

4. ## Re: Subtracting Mixed Numbers

The simplest way to do this is the use the "laws of exponents"- in particular the fact that $x^{ab}= (x^a)^b$. Here, you have $2^{5/2)= 2^{5(1/2)}= (2^{1/2})^5$ and $2^{3/2}= 2^{3(1/2)}= (2^{1/2}^3$. We can write the expression as $(2^{1/2})^5- (2^{1/2})^3$ and factor out $(2^{1/2})^3$ ( $2^{5/2}= 2^{3/2+ 2/2}= 2^{1+ 3/2}$.)

$2^{5/2}- 2^{3/2}= (2^{3/2})(2- 1)= 2^{3/2}$.