Question

Tính giá trị của biểu thức, tính nhanh nếu có thể

9) \(\frac{13}{50}\) + 9% + \(\frac{41}{100}\) + 24%

10) 2011,2012 . 2000 ( \(\frac{5}{6}\) - \(\frac{1}{3}\) - 50% ) . 1,234 + 10

11) \(\frac{120-0,5.40.5.0,2.20.0,25-20}{1+5+9+........+33+37}\)

12) \(6\frac{2}{7}+7\frac{3}{5}+8\frac{6}{9}+9\frac{1}{4}+\frac{2}{5}+\frac{5}{7}+\frac{1}{3}+\frac{3}{4}+1997\)

Answer 1

13/50+9/100+41/100+12/50

=(13/50+12/50)+(9/100+41/100)

=1/2+1/2

=1

Answer 2

11) Ta có:

\(\frac{120-0,5.40.5.0,2.20.0,25-20}{1+5+9+...+33+37}\)

\(=\frac{120-\left(0,5.40\right).\left(5.0,2\right).\left(20.0,25\right)-20}{1+5+9+...+33+37}\)

\(=\frac{120-20.1.5-20}{1+5+9+...+33+37}\)

\(=\frac{120-100-20}{1+5+9+...+33+37}\)

\(=\frac{0}{1+5+9+...+33+37}=0\)