Tìm GTNN:

1. G=2x²+9y²-6xy-6x-12y+2021

2. H=2x²+4y²+4xy+4y+9

3. I= x²-4xy+5y²+10x-22y+28

4. K=x²+5y²-4xy+6x-14y+15

Tìm giá trị nhỏ nhất của biểu thức:

1. x²-2x-5

2. 3x²+5x-2

3. 2x²-7x+7

7, The children couldn’t go swimming because the water was very cold.

Because of  …………………………………………………………………………..

Rewrite the sentences that the meaning unchanged .

1. Where do you live?

What …………………………………………………………………………………

 2. Why were you absent from class last Monday?

Why didn’t …………………………………………………………………………