Tính giá trị biểu thức sau: $A=\Big(\dfrac{1}{2}-\dfrac{1}{3} \Big)\Big(\dfrac{1}{2}-\dfrac{1}{5} \Big)\Big(\dfrac{1}{2}-\dfrac{1}{7} \Big)\cdots \Big(\dfrac{1}{2}-\dfrac{1}{99} \Big)$.

Tính bằng cách hợp lí: $B=\Big(1-\dfrac{1}{3} \Big)\Big(1-\dfrac{1}{6} \Big)\Big(1-\dfrac{1}{10} \Big)\Big(1-\dfrac{1}{15} \Big)\cdots \Big(1-\dfrac{1}{210} \Big)$.

Tính giá trị các biểu thức: $C=\Big(1-\dfrac{1}{4} \Big)\Big(1-\dfrac{1}{9} \Big)\Big(1-\dfrac{1}{16} \Big)\cdots \Big(1-\dfrac{1}{400} \Big)$.

Tính giá trị biểu thức sau: $C=\Big(1-\dfrac{1}{1+2} \Big)\Big(1-\dfrac{1}{1+2+3} \Big)\Big(1-\dfrac{1}{1+2+3+4} \Big)\cdots \Big(1-\dfrac{1}{1+2+3+\cdots +2\,016} \Big)$.

Tính giá trị biểu thức sau: $A=\dfrac{{{2}^{2}}}{1\cdot 3}\cdot \dfrac{{{3}^{2}}}{2\cdot 4}\cdot \dfrac{{{4}^{2}}}{3\cdot 5}\cdot \cdot \cdot \dfrac{{{20}^{2}}}{19\cdot 21}$.

Tính giá trị biểu thức sau:$A=\Big(\dfrac{1}{4}-1 \Big)\cdot \Big(\dfrac{1}{9}-1 \Big)\cdot \Big(\dfrac{1}{16}-1 \Big)\cdots \Big(\dfrac{1}{100}-1 \Big)\cdot \Big(\dfrac{1}{121}-1 \Big)$.

Thực hiện phép tính: $\Big(\dfrac{1}{{{2}^{2}}}-1 \Big)\Big(\dfrac{1}{{{3}^{2}}}-1 \Big)\Big(\dfrac{1}{{{4}^{2}}}-1 \Big)\cdots \Big(\dfrac{1}{{{100}^{2}}}-1 \Big)\Big(\dfrac{1}{{{101}^{2}}}-1 \Big)$.

Thực hiện phép tính: $P=\Big(1+\dfrac{7}{9} \Big)\Big(1+\dfrac{7}{20} \Big)\Big(1+\dfrac{7}{33} \Big)\cdots \Big(1+\dfrac{7}{2\,900} \Big)$.

Tính hợp lí giá trị biểu thức $B=\Big(1+\dfrac{1}{1\cdot 3} \Big)\cdot \Big(1+\dfrac{1}{2\cdot 4} \Big)\cdot \Big(1+\dfrac{1}{3\cdot 5} \Big)\cdots \Big(1+\dfrac{1}{19\cdot 21} \Big)$.

Tính giá trị biểu thức: $B=\dfrac{\left(1+17 \right)\Big(1+\dfrac{17}{2} \Big)\Big(1+\dfrac{17}{3} \Big)\cdots \Big(1+\dfrac{17}{19} \Big)}{\left(1+19 \right)\Big(1+\dfrac{19}{2} \Big)\Big(1+\dfrac{19}{3} \Big)\cdots \Big(1+\dfrac{19}{17} \Big)}$.