9/10*20/27+5/16:10/24-5/9*1 7/20

$\frac{9}{10} \times \frac{20}{27} + \frac{5}{16} \div \frac{10}{24} - \frac{5}{9} \times 1 \: \frac{7}{20} = \frac{9}{10} \times \frac{20}{27} + \frac{5}{16} \div \frac{10}{24} - \frac{5}{9} \times \frac{27}{20} = 2/3$

$1) \: \frac{9}{10} \times \frac{20}{27} = \frac{9 \times 20}{10 \times 27} = \frac{1 \times 2}{1 \times 3} = \frac{2}{3}$

2) 5/16:10/24=5/16×24/10=5×24/16×10=1×3/2×2=3/4

3) 5/9×27/20=5×27/9×20=1×3/1×4=3/4

4) 2/3+3/4=2/3^4+3/4^3=2×4/3×4+3×3/4×3=8/12+9/12=17/12

5) 17/12-3/4=17/12-3/4^3=17/12-3×3/4×3=17/12-9/12=8/12=

= 8:4/12:4=2/3

Ответ: 2/3