Question

даю 10баллов решите 3 задание

Answer 1

▪ 1)
$7.8 times frac{4}{13} - 61.5 div 13 frac{2}{3} + 198.8 = 2.4 - 4.5 + 198.8 = - 2.1 + 198.8 = 196.7\ \ 1)7.8 times frac{4}{13} = frac{78 times 4}{10 times 13} = frac{6 times 2}{5} = frac{12}{5} = 2 frac{2}{5} = 2.4 \ 2) : 61.5 div 13 frac{2}{3} = frac{615}{10} div frac{41}{3} = frac{123 times 3}{2 times 41} = frac{3 times 3}{2} = frac{9}{2} = 4.5 \ 3) : 2.4 - 4.5 = - 2.1 \ 4) : - 2.1 + 198.8 = 196.7$

▪2)
$19.25 times frac{5}{11} + 5.76 times frac{5}{12} - 13.009 = frac{1925 times 5}{100 times 11} + frac{576 times 5}{100 times 12} - 13.009 = frac{7 times 5}{4 } + frac{12}{5} - 13.009 = frac{35}{4} + 2 frac{2}{5} - 13.009 = 8 frac{3}{4} + 2.4 - 13.009 = 8.75 + 2.4 - 13.009 = 11.15 - 13.009 = - 1.859$
▪3)
$4.625 times 2 frac{2}{15} div 2.96 - 2 frac{4}{7} = 4frac{625}{1000} times frac{32}{15} div 2 frac{96}{100} - 2 frac{4}{7} = 4 frac{5}{8} times frac{32}{15} div 2 frac{24}{25} - 2 frac{4}{7} = frac{37 times 32}{8 times 15} div frac{74}{25} - 2 frac{4}{7} = frac{37 times 4 times 25}{15 times 74} - 2 frac{4}{7} = frac{2 times 5}{3 } - 2 frac{4}{7} = 3 frac{1}{3} - 2 frac{4}{7} = 1 frac{7 - 12}{21} = 1 - frac{5}{21} = frac{16}{21}$
▪4)
$30.25 div 4 frac{5}{7} div 1.05 - 2 frac{1}{6} = 30 frac{1}{4} div frac{33}{7} div 1 frac{1}{20} - 2 frac{1}{6} = frac{121 times 7 times 20}{4 times 33 times 21} - 2 frac{1}{6} = frac{11 times 5}{3 times 3} - 2 frac{1}{6} = 6 frac{1}{9} - 2 frac{1}{6} = 4 frac{2 - 3}{18} = 4 - frac{1}{18} = 3 frac{17}{18}$