K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

a: \(=\dfrac{x^2-x+1-4x}{xy}=\dfrac{x^2-5x+1}{xy}\)

b: \(=\dfrac{5xy^2-x^2y+4xy^2+xy^2}{3xy}\)

\(=\dfrac{10xy^2-x^2y}{3xy}=\dfrac{xy\left(10y-x\right)}{3xy}=\dfrac{10y-x}{3}\)

d: \(\dfrac{2x+4}{10}-\dfrac{2-x}{15}\)

\(=\dfrac{x+2}{5}+\dfrac{x-2}{15}\)

\(=\dfrac{3x+6+x-2}{15}=\dfrac{4x+4}{15}\)

e: \(=\dfrac{x+1}{2\left(x-1\right)}-\dfrac{x^2+3}{2\left(x-1\right)\left(x+1\right)}\)

\(=\dfrac{x^2+2x+1-x^2-3}{2\left(x-1\right)\left(x+1\right)}\)

\(=\dfrac{2\left(x-1\right)}{2\left(x-1\right)\left(x+1\right)}=\dfrac{1}{x+1}\)

16 tháng 1 2018

Câu 2 sai đề nhé 

Phải là:(x-999)/99+(x-896)/101+(x-789/103)=6

a: \(=3x^3-2x^2+5x\)

b: \(=x^3-2x^2+3x+6x^2-12x+18\)

\(=x^3+4x^2-9x+18\)

c: \(=2x^2-6xy+6xy-15y^2=2x^2-15y^2\)

d: \(=\left(x+3\right)\left(x^2-9\right)-x^3+27\)

\(=x^3-9x+3x^2-27-x^3+27=3x^2-9x\)

26 tháng 12 2018

1,4x2.(5x3+2x-1)

=4x2.5x3+4x2.2x-4x2.1

20x5+8x3-4x2

2,4x3y2:x2

=4xy2

3,(15x2y3-10x3y3+6xy):5xy

15x2y3:5xy-10x3y3:5xy+6xy:5xy

3xy2-2x2y2+\(\dfrac{6}{5}\)

26 tháng 12 2018

cảm ơn bạn nhé ^^

13 tháng 12 2022

1: \(=20x^5+8x^3-4x^2\)

2: \(=4xy^2\)

3: \(=3xy^2-2x^2y^2+\dfrac{6}{5}\)

4: \(=\dfrac{5x^3+10x^2+4x^2+8x+4x+8}{x+2}=5x^2+4x+4\)

5: \(=\dfrac{7}{2x}+\dfrac{11}{3y^2}=\dfrac{21y^2+22x}{6xy^2}\)

6: \(=\dfrac{4x^2-7x+3}{\left(4x-7\right)\left(x+2\right)}\)

7: \(=\dfrac{3x+3y-2x^3+2x^2y}{\left(x-y\right)\left(x+y\right)}\)

8: \(=\dfrac{1}{2}x^2y^2\left(4x^2-y^2\right)=2x^4y^2-\dfrac{1}{2}x^2y^4\)

9: \(=\left(x-\dfrac{1}{4}\right)\left(4x-1\right)=4\left(x-\dfrac{1}{4}\right)^2=4\left(x^2-\dfrac{1}{2}x+\dfrac{1}{16}\right)\)

\(=4x^2-2x+\dfrac{1}{4}\)

10: \(=\dfrac{3x^2+6-x}{x\left(2x+6\right)}=\dfrac{2x+6}{x\left(2x+6\right)}=\dfrac{1}{x}\)

11: \(=\dfrac{x+1}{2}-\dfrac{3}{x-1}\)

\(=\dfrac{x^2-7}{2\left(x-1\right)}\)

12: \(=\dfrac{x^2-xy}{\left(x-y\right)\left(x+y\right)}=\dfrac{x}{x+y}\)

15:=x^3-y^3+2

13 tháng 12 2022

1: \(=20x^5+8x^3-4x^2\)

2: \(=4xy^2\)

3: \(=3xy^2-2x^2y^2+\dfrac{6}{5}\)

4: \(=\dfrac{5x^3+10x^2+4x^2+8x+4x+8}{x+2}=5x^2+4x+4\)

5: \(=\dfrac{7}{2x}+\dfrac{11}{3y^2}=\dfrac{21y^2+22x}{6xy^2}\)

6: \(=\dfrac{4x^2-7x+3}{\left(4x-7\right)\left(x+2\right)}\)

7: \(=\dfrac{3x+3y-2x^3+2x^2y}{\left(x-y\right)\left(x+y\right)}\)

8: \(=\dfrac{1}{2}x^2y^2\left(4x^2-y^2\right)=2x^4y^2-\dfrac{1}{2}x^2y^4\)

9: \(=\left(x-\dfrac{1}{4}\right)\left(4x-1\right)=4\left(x-\dfrac{1}{4}\right)^2=4\left(x^2-\dfrac{1}{2}x+\dfrac{1}{16}\right)\)

\(=4x^2-2x+\dfrac{1}{4}\)

10: \(=\dfrac{3x^2+6-x}{x\left(2x+6\right)}=\dfrac{2x+6}{x\left(2x+6\right)}=\dfrac{1}{x}\)

11: \(=\dfrac{x+1}{2}-\dfrac{3}{x-1}\)

\(=\dfrac{x^2-7}{2\left(x-1\right)}\)

12: \(=\dfrac{x^2-xy}{\left(x-y\right)\left(x+y\right)}=\dfrac{x}{x+y}\)

15:=x^3-y^3+2

3 tháng 10 2019

https://olm.vn/hoi-dap/tim-kiem?q=Hepl+me!!!!!cho+x2+x=1.tính+giá+trị+bểu+thức:Q=x6+2x5+2x4+2x3+2x2+2x+1&id=794722

tham khảo nhé !!! chúc bạn học tốt