giúp chỉ mình cách làm bài điền từ should hay shouldnot

7 phần 3 -2 phần 3 +-21 phần 9

Tìm x , Sao cho : x^2 + 5 - 7 = 20

The last time saw Hoa was in 2012 =>.............. They started playing tennis in 2003 =>............

Cho biểu thức A= [1/(căn x+3) +(căn x+9)/(x-9)]-căn x/2 (x lớn hơn bằng 0; x khác 9) a, Rút gọn biểu thức A b, Tính giá trị của biểu thức A khi x = 16 c, Tính giá trị nguyên của x để A có giá trị nguyên Giải hộ bài này với ạ

Câu hỏi: Tìm giá trị lớn nhất của biểu thức P = 2x - 2xy - 2x² - y²

dat mot vat khoi luong 50kg tren mat san nam ngang biet luc ma sat nghi cuc dai giua vat va ban la 20N lay g=10m/s^2 tac dung vao vat theo phuong ngang mot luc bang 10N tim gia toc cua vat

khí Ozon có CTHH là O3 là hợp chất hay đơn chất

Rút gọn $\frac{2}{3x}$ - $\frac{2}{x+1}$ . ($\frac{x+1}{3x}$ - x-1): $\frac{x-1}{x}$

1/What was that ... buzzing sound ? (Mystery) 2/She lives in a very ... flat. (Luxury) 3/The receptionist was very ... and explains everything to him (Help) 4/Some ... singers earn a lot of money(Profession) 5/We didn't go on holiday because we did not have enough money. =>If we ... 6/The children couldn't go swimming because the sea was rough. => The sea was too... 7/The mechanic serviced my car last week. => I... 8/ I'm always nervous when I travel by air. => Traveling ... 9/ He couldn't afford to buy the car. => The car... 10/ "Why don't you put your luggage under the seat?", he asked. => He suggested... 11/Although he had a good salary, he was unhappy in his job. => In spite of... 12/I'm sorry I missed your birthday party. => I wish... 13/ The haven't cleaned the streets this week. => The streets... 14/ They kept me waiting for half an hour => I....