Question

Решить примеры по математике

Answer 1

Ответ: а) 8/25 или 0,32

б) 1/7

Пошаговое объяснение:

а)                                  

   $(\frac{5}{8} x-\frac{1}{5} )*\frac{3}{4} =\frac{3}{4} \\\\\frac{5}{8} x-\frac{1}{5} = \frac{3}{4} : \frac{3}{4}\\\\\frac{5}{8} x-\frac{1}{5} =1\\\\\frac{5}{8} x=\frac{1}{5} \\\\x=\frac{1}{5}:\frac{5}{8} = \frac{1}{5} *\frac{8}{5} =\frac{1*8}{5*5}=\frac{8}{25}$

б)

    $3\frac{1}{2} (\frac{2}{3}x + \frac{4}{7} )=2\frac{1}{3}\\\\\frac{2}{3}x + \frac{4}{7} = 2\frac{1}{3} : 3\frac{1}{2} \\\\\frac{2}{3} x = \frac{7}{3} :\frac{7}{2} -\frac{4}{7} \\\\\frac{2}{3}x = \frac{7*2}{3*7} -\frac{4}{7} =\frac{2}{3} -\frac{4}{7} =\frac{2*7-3*4}{21} =\frac{14-12}{21} =\frac{2}{21} \\\\x=\frac{2}{21} :\frac{2}{3} =\frac{2}{21}*\frac{3}{2} =\frac{2*3}{21*2} =\frac{1}{7} \\\\x=\frac{1}{7}$