Question

вычислите 1)4/15+3/4 2) 5/6-9/14 3)4 4/7+6 1/4 4) 5 7/8-3 5/6

Answer 1

ну вот все очень просто
1)$frac{4}{15} + frac{3}{4}= frac{4*4}{15*4}+ frac{15*3}{15*4}= frac{16}{60}+ frac{45}{60} = frac{16+45}{60} = frac{61}{60} =1 frac{1}{60}$
2)56-914=$frac{7*5}{7*6}$-$frac{3*9}{3*14}$=$frac{35}{42} - frac{27}{42}$=$frac{35-27}{42} = frac{8}{42}$=$frac{4*2}{21*2} = frac{4}{21}$
3)$4 frac{4}{7} + 6frac{1}{4}$=$frac{4*7+4}{7} + frac{6*4+1}{4}$=$frac{32}{7} + frac{25}{4} = frac{4*32}{7*4}$+$frac{7*25}{7*4}$=$frac{128}{28} + frac{175}{28}$=$frac{128+175}{28} = frac{303}{28}=$$10frac{23}{28}$
4)5 78-3 56=$frac{5*8+7}{8} - frac{3*6+5}{6}$=$frac{47}{8} - frac{23}{6} = frac{3*47}{3*8} - frac{4*23}{4*6} = frac{141}{24} - frac{92}{24}$=$frac{141-92}{24}$=$frac{49}{24} = 2frac{1}{24}$