if you want to add or subtract fractions :
1- make sure that the denominators of the fractions are equal. if they are not, then multiply each of them by a number so that they will be equal.
2- add or subtract the numerators.(if you already had multiplied the denominator of a fraction by a number, then you should multiply the numerator by the same number and do the adding or subtracting)
3- simplify it's possible
here are the answers :
[tex] \frac{3}{7} + \frac{6}{11} = \frac{33 + 42}{77} = \frac{75}{77} [/tex]
[tex] \frac{1}{3} + \frac{3}{4} = \frac{4 + 9}{12} = \frac{13}{12} = 1 \frac{1}{12} [/tex]
[tex] \frac{4}{5} + \frac{3}{7} = \frac{28 + 15}{35} = \frac{43}{35} = 1 \frac{8}{35} [/tex]
[tex] \frac{7}{12} - \frac{1}{8} = \frac{14 - 3}{24} = \frac{11}{24} [/tex]
[tex] \frac{9}{10} - \frac{2}{3} = \frac{27 - 20}{30} = \frac{7}{30} [/tex]
good luck
