lemai03

1. Tính 

    a) $\frac{49^{5}.7^{16}}{7^{18}.7^{6}}$

    b) $\frac{4^{16}.8^{20}}{2^{14}.32^{15}}$

2. Tìm $x$

    a) $\left ( \frac{3}{2}. x +\frac{4}{3} \right )^{2}=\frac{4}{9}$

    b) $\left ( \frac{7}{15}-\frac{3}{20}.x \right )^{3}=\frac{-8}{125}$

3. Rút gọn

    a) $x ^{n+1}.x ^{n+2}$

    b) $x ^{3.( n+4)}\div x^{2( n-1)}$

a) CMR: $\frac{a}{b}> \frac{a+1}{b+1}$ với $a>b>0$

b) So sánh T= $\frac{-2}{1}\times \frac{4}{3}\times \frac{6}{5}\times ...\times \frac{120}{119}$ với X= $\frac{-3}{2}\times \frac{5}{4}\times \frac{7}{6}\times ...\times \frac{121}{120}$