Question

Выполните действие: 1) 7/12+ 7/20 2) 3/8+ 1/18 3) 1/12 +11/14 4) 2/15 -7/12 5) 9/14 - 5/12 6) 19/75 + 7/50

Answer 1

$\tt\displaystyle 1)\;\frac{7}{12}+\frac{7}{20}=\frac{7*5}{60}+\frac{7*3}{60}=\frac{35+21}{60}=\frac{56}{60}=\frac{14}{15}\\\\\\2)\;\frac{3}{8}+\frac{1}{18}=\frac{3*9}{72}+\frac{1*4}{72}=\frac{27+4}{72}=\frac{31}{72}\\\\\\3)\;\frac{1}{12}+\frac{11}{14}=\frac{1*7}{84}+\frac{11*6}{84}=\frac{7+66}{84}=\frac{73}{84}\\\\\\4)\;\frac{2}{15}-\frac{7}{12}=\frac{2*4}{60}-\frac{7*5}{60}=\frac{8-35}{60}=\frac{-27}{60}=-\frac{9}{20}\\\\\\$

$\tt\displaystyle \\\\5)\;\frac{9}{14}-\frac{5}{12}=\frac{9*6}{84}-\frac{5*7}{84}=\frac{54-35}{84}=\frac{19}{84}\\\\\\6)\;\frac{19}{75}+\frac{7}{50}=\frac{19*2}{150}+\frac{7*3}{150}=\frac{38+21}{150}=\frac{59}{150}$