Tìm giá trị của x để phân thức A chia hết cho phân thức B biết: 

\(A = \frac{{{x^3} - {x^2} - x + 11}}{{x - 2}};\,\,B = \frac{{x + 2}}{{x - 2}}\).

Cho\(A = \frac{{{x^2} + {y^2} + xy}}{{{x^2} - {y^2}}}:\frac{{{x^3} - {y^3}}}{{{x^2} + {y^2} - 2xy}}\)và \(B = \frac{{{x^2} - {y^2}}}{{{x^2} + {y^2}}}:\frac{{{x^2} - 2xy + {y^2}}}{{{x^4} - {y^4}}}\).

Khi x + y = 5 hãy so sánh A và B.

She will start writing an essay about unemployment _______.

His health has improved greatly _______ .

A. before he gave up smoking

B. once he gives up smoking

C. since he gave up smoking

D. after he had given up smoking 

Since Linda participated in this youth club, she _______ more confident.

Peter was entering the construction site when he ________ a dead body on the floor.

They will launch a campaign _______ .

A. once they raise enough money

B. after they had raised enough money

C. when they raised enough money

D. as soon as they will raise enough money 

Only after he _______ from cyber-bullying did he realise how dangerous social networking sites were.

Luke will apply for this vacant position _______ .

This is the first time I _______ such an impressive art exhibition.

The last time he _______ on a luxury cruise ship was 5 years ago.

Before she _______ out with friends, Lan had done the ironing.

The family will hold a big party _______ .

Tony _______ through the wooded area when he discovered a tomb.

Last night, my husband _______ me up when I was having a terrible nightmare.

A. before they arrived at the hotel

B. without their arrival at the hotel

C. upon their arrival at the hotel

D. as they arrived at the hotel 

Only after he _______ to me did I know how to activate this device.

Roy won’t be allowed to park here _______ .

A. once she got a parking permit

B. before she got a parking permit

C. as soon as she got a parking permit

D. until she gets a parking permit 

Our attitudes towards work-life balance have changed significantly _______ .

A. before we started working from home

B. after we had started working from home

C. since we started working from home

D. until we start working from home 

Tim must be very tired because he _______ playing the violin for hours!

Before she entered the room, she _______ about the surprise party for Tom.

Martin won’t realise the importance of wearing face masks _______ .

A. after he had contracted the virus

B. until he contracts the virus

C. before he contracted the virus

D. when he contracted the virus