Question

927. сократите дробь 1) 81-27 27*54 2) 25+15 15*8 3) 9+36 9*25 4) (11+88)*12 11*60 5) 19*(29+86) 29*76 6) 17*8-12*8 80

Answer 1

1) $\frac{81-27}{27*54} = \frac{54}{27*54} = \frac{1}{27}$
2) $\frac{25+15}{15*8} = \frac{40}{15*8} = \frac{5}{15} = \frac{1}{3}$
3) $\frac{9+36}{9*25} = \frac{45}{9*25} = \frac{5}{25} = \frac{1}{5}$
4) $\frac{(11+88)*12}{11*60} = \frac{99}{11*5} = \frac{9}{5} = 1 \frac{4}{5}$
можно еще вот так: 
$\frac{(11+88)*12}{11*60} = \frac{11*12* (1+8)}{11*60} = \frac{1*9}{5} = \frac{9}{5} = 1 \frac{4}{5}$
5) $\frac{19*(29+87)}{29*76} = \frac{19*29*(1+3)}{29*76} = \frac{19*29*4}{29*76}$ = $\frac{19*4}{76} = \frac{1}{1} = 1$
6) $\frac{17*8-12*8}{80} = \frac{8*(17-12)}{80} = \frac{1*5}{10} = \frac{5}{10} = \frac{1}{2}$