\(A=\dfrac{1}{2^1}+\dfrac{1}{2^2}+...+\dfrac{1}{2^{100}}\)

\(\Rightarrow2A=1+\dfrac{1}{2^1}+\dfrac{1}{2^2}+...+\dfrac{1}{2^{99}}\)

\(\Rightarrow A=2A-A=1+\dfrac{1}{2^1}+...+\dfrac{1}{2^{99}}-\dfrac{1}{2^1}-\dfrac{1}{2^2}-...-\dfrac{1}{2^{100}}=1-\dfrac{1}{2^{100}}\)

\(=\dfrac{2^{100}-1}{2^{100}}=B\)

1. Hoa’s hair is long and blond.

=> Hoa has ______long blond hair______________.

2. Nam is too weak to lift this box.

=> Nam isn’t _____strong enough to lift this box_________.

3. Quang intends to plant trees tomorrow.

=> Quang is __________going to plant trees tomorrow_____________.

4. Keeping medicine in locked cupboards is safe.

=> It _____safe to keep medicine in locked cupboards____________.

5. The weather was too bad for us to go camping.

=> The weather wasn’t _______good enough for us to go camping___________

6. My baby sister’s eyes are brown and big.

=> My baby sister has _________big brown eyes______________

7. They intend to build a night shelter for the homeless.

=> They are ________going to build a night shelter for the homeless___________

8. Traveling at the high speed in the rain is very dangerous.

=> It ______________dangerous to travel at the high speed in the rain____________

\(2x^2-5x^3+2x^3y^3=x^2\left(2-5x+2xy^3\right)\)

3 are having

4 had

5 don't live

we saw our parents was 2 years ago