Question

найдите значение выражений: a) 1/4•4/9 b) 1/7 • 2 1/3 в) 2 2/5 • 5/6 г) (1/5+ 2/15) • 3/4 д) (1/2-1/3

Answer 1

$frac{1}{4} * frac{4}{9}= frac{1*4}{4*9}= frac{1}{9}$

$frac{1}{7} * 2frac{1}{30}= frac{1}{7} * frac{2*30+1}{30}= frac{1}{7} * frac{61}{30}= frac{1*61}{7*30}= frac{61}{210}$

$2 frac{2}{5} * frac{5}{6}= frac{5*2+2}{5} * frac{5}{6}= frac{12}{5} * frac{5}{6}= frac{12*5}{5*6}= frac{2*6*5}{5*6}= frac{2}{1}=2$

$(frac{1}{5} + frac{2}{15})* frac{3}{4} = (frac{1*3}{5*3} + frac{2}{15})* frac{3}{4} = (frac{3}{15} + frac{2}{15})* frac{3}{4} = frac{3+2}{15}* frac{3}{4} = frac{5}{15}* frac{3}{4} =$$frac{5}{5*3}* frac{3}{4} = frac{1}{3}*frac{3}{4} = frac{1*3}{3*4}= frac{1}{4}$