Question

 

 

bài này nữa thôi các anh chị :3 em cảm ơn nhiều ạ

 

Answer 1

a) \(x^2+xy+x\)

\(=x\left(x+y+1\right)\)

Thay x=77, y=22

\(=77\left(77+22+1\right)\)

\(=77.100=7700\)

b) \(x\left(x-y\right)+y\left(y-x\right)\)

\(=\left(x-y\right)\left(x-y\right)\)

\(=\left(x-y\right)^2\)

Thay x=53, y=3

\(=\left(53-3\right)^2\)

\(=50^2=2500\)

c) \(x\left(x-1\right)-y\left(1-x\right)\)

\(=\left(x+y\right)\left(x-1\right)\)

Thay x=2021, y=2029

\(=\left(2021+2019\right)\left(2021-1\right)\)

\(=4040.2020\)

\(=8160800\)