1. Tìm x, y biết:

a) \(\dfrac{x-1}{5}=\dfrac{y-2}{3}=\dfrac{z-2}{2}\) và x + 2y - z = 6

b) \(\dfrac{x}{y}=\dfrac{2}{3}\) và x² + y² = 52

2. Cho \(\dfrac{a}{b}=\dfrac{c}{d}\) . Chứng minh rằng:

a) \(\dfrac{a+b}{b}=\dfrac{c+d}{d}\)

b) \(\dfrac{ac}{bd}=\dfrac{a^2+c^2}{b^2+d^2}\)

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks.

It is natural for young people to be critical of their parents at times and to blame them for most of the (23)       between them. They have always complained, more or less justly, that their parents are old- fashioned, possessive and dominant; that they do not trust their children to deal with obstacles; (24)      they talk too much about certain problems and that they have no sense of humor, at least in parent-child relationships. I think it is true that parents often (25)   their teenage children and also forget how they themselves felt when young.

Young people often irritate their parents with their choices in clothes and hairstyles, in entertainers and music. This is not their motive. They feel cut off from the adult world into which they have not yet been accepted. (26)             _they create a culture and society of their own. Then, if it turns out that their music or entertainers or vocabulary or clothes or hairstyles irritate their parents, this gives them additional enjoyment. They feel they are superior, at least in a small way, and that they are leaders in style and taste. If you plan to control your life, co-operation can be part of that plan. You can charm others, especially parents, into doing things the ways you want. You can impress others with your sense of responsibility and (5)       , so that they will give you the authority to do what you want to do.

(Source:https://www.woyaosouti.com/topic/107813763)

Điền vào ô 23.

A. misunderstandings

B. debates

C. conflict

D. understanding

Tìm số tự nhiên x biết :

a, 2.(x – 5)+7 = 77

b,  x - 1 3 - 3 5 : 3 4 + 2 . 2 3 = 14

c,  1 + 2 + 2 2 + 2 3 + . . . + 2 2016 = 2 x - 1 - 1

d,  5 2 x - 3 - 2 . 5 2 = 5 2 . 3

các bạn cho mình biết cách giải với đc ko

tan cung la7 la dung 100phan tram

Tìm hai số a và b biết rằng ƯCLN(a,b) = 6 và BCNN(a,b) = 120

Diện tích ban đầu là 480m2