4.5 Add and subtract fractions with different denominators  (Page 6/7)

$\frac{2}{3}\text{and}\frac{3}{4}$

$\frac{3}{4}\text{and}\frac{2}{5}$

$\frac{7}{12}\text{and}\frac{5}{8}$

$\frac{9}{16}\text{and}\frac{7}{12}$

$\frac{13}{30}\text{and}\frac{25}{42}$

$\frac{23}{30}\text{and}\frac{5}{48}$

$\frac{21}{35}\text{and}\frac{39}{56}$

$\frac{18}{35}\text{and}\frac{33}{49}$

$\frac{2}{3}\text{,}\frac{1}{6},\text{and}\frac{3}{4}$

$\frac{2}{3}\text{,}\frac{1}{4},\text{and}\frac{3}{5}$

$\frac{1}{3}\text{and}\frac{1}{4},\text{LCD}=12$

$\frac{1}{4}\text{and}\frac{1}{5},\text{LCD}=20$

$\frac{5}{12}\text{and}\frac{7}{8},\text{LCD}=24$

$\frac{7}{12}\text{and}\frac{5}{8},\text{LCD}=24$

$\frac{13}{16}\text{and}\text{−}\frac{11}{12},\text{LCD}=48$

$\frac{11}{16}\text{and}\text{−}\frac{5}{12},\text{LCD}=48$

$\frac{1}{3},\frac{5}{6},\text{and}\frac{3}{4},\text{LCD}=12$

$\frac{1}{3},\frac{3}{4},\text{and}\frac{3}{5},\text{LCD}=60$

$\frac{1}{3}+\frac{1}{5}$

$\frac{1}{4}+\frac{1}{5}$

$\frac{1}{2}+\frac{1}{7}$

$\frac{1}{3}+\frac{1}{8}$

$\frac{1}{3}-\left(-\frac{1}{9}\right)$

$\frac{1}{4}-\left(-\frac{1}{8}\right)$

$\frac{1}{5}-\left(-\frac{1}{10}\right)$

$\frac{1}{2}-\left(-\frac{1}{6}\right)$

$\frac{2}{3}+\frac{3}{4}$

$\frac{3}{4}+\frac{2}{5}$

$\frac{7}{12}+\frac{5}{8}$

$\frac{5}{12}+\frac{3}{8}$

$\frac{7}{12}-\frac{9}{16}$

$\frac{7}{16}-\frac{5}{12}$

$\frac{11}{12}-\frac{3}{8}$

$\frac{5}{8}-\frac{7}{12}$

$\frac{2}{3}-\frac{3}{8}$

$\frac{5}{6}-\frac{3}{4}$

$-\frac{11}{30}+\frac{27}{40}$

$-\frac{9}{20}+\frac{17}{30}$

$-\frac{13}{30}+\frac{25}{42}$

$-\frac{23}{30}+\frac{5}{48}$

$-\frac{39}{56}-\frac{22}{35}$

$-\frac{33}{49}-\frac{18}{35}$

$-\frac{2}{3}-\left(-\frac{3}{4}\right)$

$-\frac{3}{4}-\left(-\frac{4}{5}\right)$

$-\frac{9}{16}-\left(-\frac{4}{5}\right)$

$-\frac{7}{20}-\left(-\frac{5}{8}\right)$

$1+\frac{7}{8}$

$1+\frac{5}{6}$

$1-\frac{5}{9}$

$1-\frac{3}{10}$

$\frac{x}{3}+\frac{1}{4}$

$\frac{y}{2}+\frac{2}{3}$

$\frac{y}{4}-\frac{3}{5}$

$\frac{x}{5}-\frac{1}{4}$

1. ⓐ $\frac{3}{4}+\frac{1}{6}$
2. ⓑ $\frac{3}{4}÷\frac{1}{6}$

1. ⓐ $\frac{2}{3}+\frac{1}{6}$
2. ⓑ $\frac{2}{3}÷\frac{1}{6}$

1. ⓐ $\text{−}\frac{2}{5}-\frac{1}{8}$
2. ⓑ $\text{−}\frac{2}{5}·\frac{1}{8}$

1. ⓐ $\text{−}\frac{4}{5}-\frac{1}{8}$
2. ⓑ $\text{−}\frac{4}{5}·\frac{1}{8}$

1. ⓐ $\frac{5}{n}÷\frac{8}{15}$
2. ⓑ $\frac{5}{n}-\frac{8}{15}$

1. ⓐ $\frac{3}{a}÷\frac{7}{12}$
2. ⓑ $\frac{3}{a}-\frac{7}{12}$

1. ⓐ $\frac{4}{15}·(-\frac{5}{q})$
2. ⓑ $\frac{4}{15}+(-\frac{5}{q})$

$-\frac{3}{8}÷\left(-\frac{3}{10}\right)$

$-\frac{5}{12}÷\left(-\frac{5}{9}\right)$

$-\frac{3}{8}+\frac{5}{12}$

$-\frac{1}{8}+\frac{7}{12}$

$\frac{5}{6}-\frac{1}{9}$

$\frac{5}{9}-\frac{1}{6}$

$\frac{3}{8}·\left(-\frac{10}{21}\right)$

$\frac{7}{12}·\left(-\frac{8}{35}\right)$

$-\frac{7}{15}-\frac{y}{4}$

$-\frac{3}{8}-\frac{x}{11}$

$\frac{11}{12a}·\frac{9a}{16}$

$\frac{10y}{13}·\frac{8}{15y}$

$\frac{{\left(\frac{1}{5}\right)}^2}{2+3^2}$

$\frac{{\left(\frac{1}{3}\right)}^2}{5+2^2}$

$\frac{2^3+4^2}{{\left(\frac{2}{3}\right)}^2}$

$\frac{3^3-3^2}{{\left(\frac{3}{4}\right)}^2}$

$\frac{{\left(\frac{3}{5}\right)}^2}{{\left(\frac{3}{7}\right)}^2}$

$\frac{{\left(\frac{3}{4}\right)}^2}{{\left(\frac{5}{8}\right)}^2}$

$\frac{2}{\frac{1}{3}+\frac{1}{5}}$

$\frac{5}{\frac{1}{4}+\frac{1}{3}}$

$\frac{\frac{2}{3}+\frac{1}{2}}{\frac{3}{4}-\frac{2}{3}}$

$\frac{\frac{3}{4}+\frac{1}{2}}{\frac{5}{6}-\frac{2}{3}}$

$\frac{\frac{7}{8}-\frac{2}{3}}{\frac{1}{2}+\frac{3}{8}}$

$\frac{\frac{3}{4}-\frac{3}{5}}{\frac{1}{4}+\frac{2}{5}}$

$\frac{1}{2}+\frac{2}{3}·\frac{5}{12}$

$\frac{1}{3}+\frac{2}{5}·\frac{3}{4}$

$1-\frac{3}{5}÷\frac{1}{10}$

$1-\frac{5}{6}÷\frac{1}{12}$

$\frac{2}{3}+\frac{1}{6}+\frac{3}{4}$

$\frac{2}{3}+\frac{1}{4}+\frac{3}{5}$

$\frac{3}{8}-\frac{1}{6}+\frac{3}{4}$

$\frac{2}{5}+\frac{5}{8}-\frac{3}{4}$

$12\left(\frac{9}{20}-\frac{4}{15}\right)$

$8\left(\frac{15}{16}-\frac{5}{6}\right)$

$\frac{\frac{5}{8}+\frac{1}{6}}{\frac{19}{24}}$

$\frac{\frac{1}{6}+\frac{3}{10}}{\frac{14}{30}}$

$\left(\frac{5}{9}+\frac{1}{6}\right)÷\left(\frac{2}{3}-\frac{1}{2}\right)$

$\left(\frac{3}{4}+\frac{1}{6}\right)÷\left(\frac{5}{8}-\frac{1}{3}\right)$

$x+\frac{1}{2}$ when

1. ⓐ $x=-\frac{1}{8}$
2. ⓑ $x=-\frac{1}{2}$

$x+\frac{2}{3}$ when

1. ⓐ $x=-\frac{1}{6}$
2. ⓑ $x=-\frac{5}{3}$

$x+\left(-\frac{5}{6}\right)$ when

1. ⓐ $x=\frac{1}{3}$
2. ⓑ $x=-\frac{1}{6}$

$x+\left(-\frac{11}{12}\right)$ when

1. ⓐ $x=\frac{11}{12}$
2. ⓑ $x=\frac{3}{4}$

$x-\frac{2}{5}$ when

1. ⓐ $x=\frac{3}{5}$
2. ⓑ $x=-\frac{3}{5}$

$x-\frac{1}{3}$ when

1. ⓐ $x=\frac{2}{3}$
2. ⓑ $x=-\frac{2}{3}$

$\frac{7}{10}-w$ when

1. ⓐ $w=\frac{1}{2}$
2. ⓑ $w=-\frac{1}{2}$

$\frac{5}{12}-w$ when

1. ⓐ $w=\frac{1}{4}$
2. ⓑ $w=-\frac{1}{4}$

$4p^{2}q$ when $p=-\frac{1}{2}\text{and}q=\frac{5}{9}$

$5m^{2}n\text{when}m=-\frac{2}{5}\text{and}n=\frac{1}{3}$

$8u^2{v}^3\text{when}u=-\frac{3}{4}\text{and}v=-\frac{1}{2}$

$\frac{a+b}{a-b}\text{when}a=\mathrm{-3},b=8$

$\frac{r-s}{r+s}\text{when}r=10,s=\mathrm{-5}$

Decorating Laronda is making covers for the throw pillows on her sofa. For each pillow cover, she needs $\frac{3}{16}$ yard of print fabric and $\frac{3}{8}$ yard of solid fabric. What is the total amount of fabric Laronda needs for each pillow cover?

Baking Vanessa is baking chocolate chip cookies and oatmeal cookies. She needs $1\frac{1}{4}$ cups of sugar for the chocolate chip cookies, and $1\frac{1}{8}$ cups for the oatmeal cookies How much sugar does she need altogether?

Explain why it is necessary to have a common denominator to add or subtract fractions.

Explain how to find the LCD of two fractions.