Question

Посчитайте : ) 1) (8 2/3 +5 *1 1/8 - 10 * 2 2/8): (8 1/2 - 5 3/4)=? 2) -3 1/2 + 12 5/18 + 4 11/24 - 4 3/8=? 3) 6,25 * 2 1/25 - (2,064 - 1 3/4) : 2/5=?

Answer 1

$(8 \frac{2}{3} +5 *1 \frac{1}{8} - 10 * 2 \frac{1}{8}): (8 \frac{1}{2} - 5 \frac{3}{4})= \\ \\ =(\frac{26}{3} +5 *\frac{9}{8} - 10*\frac{17}{8}): (\frac{17}{2} - \frac{23}{4})= \\ \\ =(\frac{26}{3} +\frac{45}{8} - \frac{170}{8}): (\frac{17}{2} - \frac{23}{4})= \\ \\ =(\frac{26}{3} - \frac{125}{8}): (\frac{17}{2} - \frac{23}{4})= \\ \\ =(\frac{26*8-125*3}{24} ): (\frac{17*2-23}{4})= \\ \\ =\frac{-167}{24} : \frac{11}{4}=-\frac{167}{24}* \frac{4}{11}=- \frac{167}{66} =-2 \frac{35}{66}$

$-3 \frac{1}{2} + 12 \frac{5}{18} + 4 \frac{11}{24} - 4 \frac{3}{8}= -\frac{7}{2} + \frac{221}{18} + \frac{107}{24} - \frac{35}{8}= \\ \\ =\frac{-7*36+221*4+107*3-35*9}{72}=\frac{-252+884+321-315}{72} = \\ \\ =\frac{638}{72} = \frac{319}{36} =8 \frac{31}{36}$

$6,25 * 2 \frac{1}{25} - (2,064 - 1 \frac{3}{4}) : \frac{2}{5}=6 \frac{25}{100} * 2 \frac{1}{25} - (2 \frac{64}{1000} - 1 \frac{3}{4}) : \frac{2}{5}= \\ \\ =6 \frac{1}{4} * 2 \frac{1}{25} - (2 \frac{8}{125} - 1 \frac{3}{4}) : \frac{2}{5}=\frac{25}{4} * \frac{51}{25} - (\frac{258}{125} - \frac{7}{4}) : \frac{2}{5}= \\ \\ =\frac{51}{4} - (\frac{258*4-7*125}{500} ) : \frac{2}{5}=\frac{51}{4} - \frac{157}{500} : \frac{2}{5}=\frac{51}{4} - \frac{157}{500} * \frac{5}{2}=$

$=\frac{51}{4} - \frac{157}{200}= \frac{51*50-157}{200} = \frac{2393}{200} =11 \frac{193}{200} =11,965$