# How do you simplify 15 + 3[(5-1)(7-2)2-4] using PEMDAS?

Aug 29, 2016

$123$

#### Explanation:

Count the number of terms first. Each term must simplify to a single answer and these are added or subtracted in the LAST step.

Within each term - do parentheses/brackets first, then work from the strongest operations of powers and roots, followed by multiplication and division. Only then are the additions and subtractions done.

$\textcolor{m a \ge n t a}{15} + \textcolor{\mathmr{and} a n \ge}{3 \times} \left[\textcolor{red}{\left(5 - 1\right) \left(7 - 2\right)} \textcolor{b l u e}{\times 2} \textcolor{\lim e}{- 4}\right]$ has two terms.

=$\textcolor{m a \ge n t a}{15} + \textcolor{\mathmr{and} a n \ge}{3 \times} \left[\textcolor{red}{\left(4\right)} \times \textcolor{red}{\left(5\right)} \textcolor{b l u e}{\times 2} \textcolor{\lim e}{- 4}\right]$

=$\textcolor{m a \ge n t a}{15} + \textcolor{\mathmr{and} a n \ge}{3 \times} \left[\textcolor{red}{20} \textcolor{b l u e}{\times 2} \textcolor{\lim e}{- 4}\right]$

=$\textcolor{m a \ge n t a}{15} + \textcolor{\mathmr{and} a n \ge}{3 \times} \left[\textcolor{red}{40} \textcolor{\lim e}{- 4}\right]$

=$\textcolor{m a \ge n t a}{15} + \textcolor{\mathmr{and} a n \ge}{3 \times} \textcolor{red}{36}$

=$\textcolor{m a \ge n t a}{15} + \textcolor{\mathmr{and} a n \ge}{108}$

=$123$