Question

Найдите неизвестные член пропорции

Answer 1

Вправа 20

1) -2,3*(-11,8) = -9,2х

27,14 = -9,2х

х = 27,14 : (-9,2) = -2,95

2) -26х = $\frac{3}{4}*\frac{7}{3}$

-26х = $\frac{7}{4}$

х = $\frac{7}{4} : (-26)$

х = $\frac{7}{4} * (-\frac{1}{26} )$

х = $-\frac{7}{104}$

3) $\frac{18}{5} * (-\frac{11}{9} ) = -\frac{12x}{11}$

$-\frac{22}{5}=-\frac{12x}{11}$

$x=-\frac{22}{5} :(-\frac{12}{11} )=-\frac{22}{5} *(-\frac{11}{12} )=\frac{11*11}{5*6}$

$x=\frac{121}{30}=4\frac{1}{30}$

4) $-\frac{24}{5}*(-\frac{8}{3} )=-\frac{18}{5}x$

$\frac{64}{5}=-\frac{18}{5}x$

$x=\frac{64}{5}: (-\frac{18}{5} ) =-\frac{64*5}{5*18}=-\frac{32}{9}=-3\frac{5}{9}$

Вправа 21

$(\frac{47}{3} -\frac{65}{4} )-(17\frac{12}{12}-15\frac{7}{12} )=(\frac{188-195}{12} )-2\frac{5}{12} =-\frac{7}{12} -2\frac{5}{12}=\frac{-7-29}{12} =\frac{-36}{12}=-3$