giải chi tiết giúp mk nhé,mk đang cần rất gấp

Làm nhanh giúp mình nha. Cảm ơn.

4/7 + 1/4 : 2/3 = ( còn nữa ạ )

Cho tứ giác ABCD, I, J theo thứ tự là trung điểm của AD và BC. Chứng minh: vectorIJ = 1/2vectorAB + 1/2vectorDC

tại sao trong quá trình mang thai người phụ nữ ko mang thai tiếp tại sao có chu kì kinh nguyệt ở phụ nữ

giai pt a) 2+ $\sqrt{2x+1}$=x b) $\sqrt{ $\frac{2x+5}{x+1}$ }$ =3 c) $\sqrt{2+$\sqrt{3x-5}$ }$= $\sqrt{x+1}$

Tính (8+2 √15) ×( √6 - √10) ×($\sqrt{4-√15}$ (3+ √5) ×($\sqrt{6-2√5 + 3-√5)}$ × (6+2 √5)

a) Rút gọn: $\frac{√54 + 3 √14} {√ 12 + √28}$ b) Rút gọn rồi tính giá trị biểu thức A= $\sqrt{$\frac{(x-6)^4}{(5-x)^2}$}$ + $\frac{x^2+36}{x-5}$ tại x=4 B= $\frac{3}{x^2-y^2}$ *$\sqrt{$\frac{3x^2+6xy+3y^2}{9}$ }$ tại x=-1, y=2

thực hiện phép tính a) (2 √12 - 3 √15 - √135) × √3 b) 2 √1008 - 3 √100 - 2 √448 + √252 c) 3$\sqrt{5√48 + 2√75+$\sqrt{40√12}$}$

V. Read the following passage and answer the questions below (10 points) The tiny village of Frinley is said to possess a “cursed tree”. Because the tree was mentioned in a newspaper, the number of visitors to Frinley has now increased. The tree was planted near a church fifty years ago, but it is only in recent years that it has gain an evil reputation. It is said that if anyone touched the tree, he will have bad luck; If he picks a leaf, he will die. Many villagers believe that the tree has already claimed a number of victims. The vicar has been asked to have the tree cut down, but so far he has refused. He has pointed out that the tree is a useful source of income as tourists have come from all parts of the country to see it. In spite of all that has been said, the tourists have picked leaves and cut their names on the tree-trunk. So far, not one of them has been truck down by sudden death! Questions: 1.Where and when the tree planted? 2.What has the tree got in recent years? 3.What will happen to a man if he touches the tree? 4Why is the tree a useful source of income? 5.Are the visitors afraid of what has been said about the tree?