Hướng dẫn mình với ạ. (50 - 55 luôn ạ)

Tìm x,yz X + Y = 4 Y x Z = 6 Z = 6 : Y giúp ạ

Mong mn giúp ạ Điền vào khoảng trống với các từ đã cho 1. My best friend is Lucas. He ... (is/has) tall. In fact he is the tallest boy in my class. He ... (is/has) very funny and kind. He ... (is/has) short brown hair and dark brown eyes. He’s always there when I need him, in good or bad times. 2. My best friend is Ha. We have known each other for almost 10 years. She ... (is/has) long black hair and big brown eyes. She ... (isn’t/doesn’t have) very tall but she ... (is/has) so adorable. I like her because she is always beside me. 3. My best friend ... (is/has) a plump face and short hair. She ... (is/has) clever and hard-working but she ... (is/has) also very funny. She makes jokes and we all laugh. She ... (is/has) good manners as well. All the students in my class love her.

Rút gọn biểu thức: a) (x^2 – 1)^3 – ( x^4 + x^2 +1)(x^2 – 1); b) (x^4 – 3x^2 + 9)(x^2 + 3) – (3 + x^2)^3 c) 4(x + 1)^4 + (2x – 1)^2 – 8(x – 1)(x + 1). d) ( a + b – c)^2 – (a + b)^2 + 2c(a + b)

viết dưới dạng tích hoặc luỹ thừa a, x^2 -10x +25 b, 1 +12x +36x^2 c, 4x^2 +4x+1 d, x^2/4 +2xy +4y^2 e, x^3 +6x^2+ 12x +8 f, 27x^3 -54x^2y + 36xy^2 -8y^3

fill in each blank with the correct conjunction 1 get up early.................... do more exercise 2 eat less junk food................ eat more fruit and vegetables 3 the weather is very cold today..................... i should put on a coat 4 watch less tevision.................. you can protect your eyes 5 if you spend less time on computer games you will have more time for outdoor activities........... television programmes 6 i have a lot of homework to do this evening.............. i don't have time watch the football match 7 take up a new hobby............ you'll have some new friends complete the short conversations with the words in the box then practives them with a partner hurt broke toothache head 1 a does your....................... hurt b yes, i ran into a tree 2 what's matter b i..................... my toe in the game yesterdaay giup mk ho cai

Lm hộ em bài này với ạ. Em cảm ơn nhiều ạ

Tìm x biết c) 3x(x - 2) - x^2 + 2x = 0 d) x + 5 = 2(x+5)^2 e) 4x^2 – 25 – (2x – 5)(2x + 7) = 0 f) x^2 + x -12 = 0

Cho tam giác ABC có các đường cao BE và CF cắt nhau tại H ( E thuộc AC; F thuộc AB). Gọi I K lần lượt là trung điểm cạnh AH,BC a, Chứng minh FK vuông góc với FI b,Cho AH=6cm,BC=8cm . Tính IK

cho biết tỉ lệ nguyên tử hoặc số phân tử của từng cặp chất trong phân ứng lập pthh a,phân hủy kaliclorua→→kaliclorua+khí oxi b, natrinitrat→→natri nitrat + khí oxi c, sắt+brôm→→sắt 3 brômua d, natri hidroxit+axit sunfua →→natri sunfat + nước e, nhôm+oxit →→nhôm oxit mong mn giúp e ạ