Question

помогите решить 1,2,3,4

Answer 1

$1) frac{6*5*126}{15*12*21} = frac{6}{3*2} = frac{2}{2} =1$
$2) frac{5}{6} - frac{4}{15} = frac{25-8}{30} = frac{17}{30}$
$3) 3frac{1}{2} : frac{4}{9} = frac{7}{2} * frac{9}{4} = frac{63}{8} =7 frac{7}{8}$
$4) 245* frac{5}{7} =35*5=175$