Question

687. 1)2/3х-1/2х
2)1/4х+1/3х
3)-7/12у-5/6у
4)8/15у-2/5у
5)5/9m+2/3m
6)3/4m-1/6m
помагите пж ​

Answer 1

Пошаговое объяснение:

$1) \dfrac{2}{3} x-\dfrac{1}{2} x=\left( \dfrac{2}{3} -\dfrac{1}{2}\right) \cdot x=\left( \dfrac{2}{3}^{\backslash2}-\dfrac{1}{2}^{\backslash3}\right) \cdot x=\dfrac{4-3}{6}\cdot x=\dfrac{1}{6} x;$

$2) \dfrac{1}{4} x+\dfrac{1}{3} x=\left( \dfrac{1}{4} +\dfrac{1}{3}\right) \cdot x=\left( \dfrac{1}{4}^{\backslash3}+\dfrac{1}{3}^{\backslash4}\right) \cdot x=\dfrac{3+4}{12}\cdot x=\dfrac{7}{12} x;$

$3) -\dfrac{7}{12} y-\dfrac{5}{6} y=\left( -\dfrac{7}{12} -\dfrac{5}{6}\right) \cdot y=\left( -\dfrac{7}{12}^{\backslash1}-\dfrac{5}{6}^{\backslash2}\right) \cdot y=\dfrac{-7-10}{12}\cdot y=-\dfrac{17}{12} y;$

$4) \dfrac{8}{15} y-\dfrac{2}{5} y=\left( \dfrac{8}{15} -\dfrac{2}{5}\right) \cdot y=\left( \dfrac{8}{15}^{\backslash1}-\dfrac{2}{5}^{\backslash3}\right) \cdot y=\dfrac{8-6}{15}\cdot y=\dfrac{2}{15} y;$

$5) \dfrac{5}{9} m+\dfrac{2}{3} m=\left( \dfrac{5}{9} +\dfrac{2}{3}\right) \cdot m=\left( \dfrac{5}{9}^{\backslash1}+\dfrac{2}{3}^{\backslash3}\right) \cdot m=\dfrac{5+6}{9}\cdot m=\dfrac{11}{9} m;$

$6) \dfrac{3}{4} m-\dfrac{1}{6} m=\left( \dfrac{3}{4} -\dfrac{1}{6}\right) \cdot m=\left( \dfrac{3}{4}^{\backslash3}-\dfrac{1}{6}^{\backslash2}\right) \cdot m=\dfrac{9-2}{12}\cdot m=\dfrac{7}{12} m.$