## Elementary Algebra

$= - \frac{31}{20}$
1. Substitute the values into the specific variables $= 2(-\frac{2}{5}) - (-\frac{3}{4}) - 3(\frac{1}{2})$ 2. Follow the acronym PEDMAS: P: arenthesis E: ponents D:ivision M:ultiplication A:ddition S:ubtraction $=$ P.E.D.M.A.S This is used to determine which order of operations is completed first from top to bottom. For example, you would complete the division of two numbers before the addition of another two numbers. In this case, we multiply before subtracting: $= -\frac{4}{5} + \frac{3}{4} - \frac{3}{2}$ $=-\frac{16}{20}+\frac{15}{20}-\frac{30}{20}$ $= - \frac{1}{20} - \frac{30}{20}$ $= - \frac{31}{20}$