# How do you simplify (3) square root of 98 - (4) square root of 28?

Jul 22, 2015

$21 \sqrt{2} - 8 \sqrt{7}$
$\textcolor{w h i t e}{\text{XXXX}}$$\textcolor{w h i t e}{\text{XXXX}}$(Unfortunately it doesn't improve from here)

#### Explanation:

$3 \sqrt{98} - 4 \sqrt{28}$

$\textcolor{w h i t e}{\text{XXXX}}$$= 3 \cdot \sqrt{2 \times 7 \times 7} - 4 \cdot \sqrt{2 \times 2 \times 7}$

$\textcolor{w h i t e}{\text{XXXX}}$$= 3 \cdot 7 \sqrt{2} - 4 \cdot 2 \sqrt{7}$

$\textcolor{w h i t e}{\text{XXXX}}$$= 21 \sqrt{2} - 8 \sqrt{7}$

Sep 22, 2015

Using the PEMDAS sequence you first calculate the square roots, then multiply them by the associated number, and finally combine those two numbers for the simplified answer.

#### Explanation:

PEMDAS is an acronym to remember the priority sequence of calculations.
P = parentheses ( )
E = exponents ^ or **
M = multiplication
D = division