\(x^2-3x+xy-3x\)

\(=x^2+xy-6x\)

\(=x.\left(x+y-6\right)\)

bài nào hả bạn

Cái đè bài đâu ?

Mik chỉ cần đáp án thôi nhé, ko cần vẽ trục số

\(\dfrac{2x-3}{5}-x+2\ge\dfrac{x}{3}\)

\(\Leftrightarrow3\left(2x-3\right)-15\left(x+2\right)\ge5x\)

\(\Leftrightarrow6x-9-15x+30\ge5x\)

\(\Leftrightarrow6x-15x-5x\ge9+30\)

\(\Leftrightarrow-14x\ge-21\)

\(\Leftrightarrow x\le\dfrac{21}{14}\le\dfrac{3}{2}\)

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lâu rồi cũng không nhớ cách làm :v

a: \(\frac{25}{14x^2y}=\frac{25\cdot3\cdot y^4}{14x^2y\cdot3y^4}=\frac{75y^4}{42x^2y^5}\)

\(\) \(\frac{14}{21xy^5}=\frac{14\cdot2\cdot x}{21xy^5\cdot2x}=\frac{28x}{42x^2y^5}\)

b: \(\frac{11}{102x^4y}=\frac{11\cdot y^2}{102x^4y\cdot y^2}=\frac{11y^2}{102x^4y^3}\)

\(\frac{3}{34xy^3}=\frac{3\cdot3\cdot x^3}{34xy^3\cdot3x^3}=\frac{9x^3}{102x^4y^3}\)

c: \(\frac{3x+1}{12xy^4}=\frac{\left(3x+1\right)\cdot3\cdot x}{12xy^4\cdot3x}=\frac{9x^2+3x}{36x^2y^4}\)

\(\frac{y-2}{9x^2y^3}=\frac{\left(y-2\right)\cdot4y}{4y\cdot9x^2y^3}=\frac{4y^2-8y}{36x^2y^4}\)

d: \(\frac{1}{6x^3y^2}=\frac{1\cdot6\cdot y^2}{6x^3y^2\cdot6y^2}=\frac{6y^2}{36x^3y^4}\)

\(\frac{x+1}{9x^2y^4}=\frac{\left(x+1\right)\cdot4\cdot x}{9x^2y^4\cdot4x}=\frac{4x^2+4x}{36x^3y^4}\)

\(\frac{x-1}{4xy^3}=\frac{\left(x-1\right)\cdot9\cdot x^2y}{4xy^3\cdot9x^2y}=\frac{9x^3y-9x^2y}{36x^3y^4}\)

e: \(\frac{3+2x}{10x^4y}=\frac{\left(2x+3\right)\cdot12\cdot y^4}{10x^4y\cdot12y^4}=\frac{24xy^4+36y^4}{120x^4y^5}\)

\(\frac{5}{8x^2y^2}=\frac{5\cdot15\cdot x^2y^3}{8x^2y^2\cdot15x^2y^3}=\frac{75x^2y^3}{120x^4y^5}\)

\(\frac{2}{3xy^5}=\frac{2\cdot40\cdot x^3}{3xy^5\cdot40x^3}=\frac{80x^3}{120x^4y^5}\)

f: \(\frac{4x-4}{2x\left(x+3\right)}=\frac{\left(4x-4\right)\cdot3\cdot\left(x+1\right)}{2x\left(x+3\right)\cdot3\cdot\left(x+1\right)}=\frac{12\left(x-1\right)\left(x+1\right)}{6x\left(x+3\right)\left(x+1\right)}=\frac{12x^2-12}{6x\left(x+3\right)\left(x+1\right)}\)

\(\frac{x-3}{3x\left(x+1\right)}=\frac{\left(x-3\right)\cdot2\cdot\left(x+3\right)}{3x\left(x+1\right)\cdot2\cdot\left(x+3\right)}=\frac{2\left(x^2-9\right)}{6x\left(x+1\right)\left(x+3\right)}\)

g: \(\frac{2x}{\left(x+2\right)^3}=\frac{2x\cdot2x}{2x\left(x+2\right)^3}=\frac{4x^2}{2x\left(x+2\right)^3}\)

\(\frac{x-2}{2x\left(x+2\right)^2}=\frac{\left(x-2\right)\left(x+2\right)}{2x\left(x+2\right)^3}=\frac{x^2-4}{2x\left(x+2\right)^3}\)

h: \(\frac{5}{3x^3-12x}=\frac{5}{3x\left(x^2-4\right)}=\frac{5}{3x\left(x-2\right)\left(x+2\right)}\)

\(=\frac{5\cdot2\cdot\left(x+3\right)}{3x\left(x-2\right)\left(x+2\right)\cdot2\cdot\left(x+3\right)}=\frac{10x+30}{6x\left(x-2\right)\left(x+2\right)\left(x+3\right)}\)

\(\frac{3}{\left(2x+4\right)\left(x+3\right)}=\frac{3}{2\left(x+2\right)\left(x+3\right)}\)

\(=\frac{3\cdot3\cdot x\left(x-2\right)}{3x\left(x-2\right)\cdot2\left(x+2\right)\left(x+3\right)}=\frac{9x^2-18x}{6x\left(x-2\right)\left(x+2\right)\left(x+3\right)}\)

\(a,PT\left(1\right)=\dfrac{75y^4}{42x^2y^5};PT\left(2\right)=\dfrac{28x}{42x^2y^5}\\ b,PT\left(1\right)=\dfrac{11y^2}{102x^4y^3};PT\left(2\right)=\dfrac{9x^3}{10x^4y^3}\\ c,PT\left(1\right)=\dfrac{3x\left(3x+1\right)}{36x^2y^4};PT\left(2\right)=\dfrac{4y\left(y-2\right)}{36x^2y^4}\\ d,PT\left(1\right)=\dfrac{6y^2}{36x^3y^4};PT\left(2\right)=\dfrac{4x\left(x+1\right)}{36x^3y^4};PT\left(3\right)=\dfrac{9x^2y\left(x-1\right)}{36x^3y^4}\)

\(e,PT\left(1\right)=\dfrac{12y^4\left(3+2x\right)}{120x^4y^5};PT\left(2\right)=\dfrac{75x^2y^3}{120x^4y^5};PT\left(3\right)=\dfrac{8x^3}{120x^4y^5}\\ f,PT\left(1\right)=\dfrac{3\left(x+1\right)\left(4x-4\right)}{6x\left(x+3\right)\left(x+1\right)};PT\left(2\right)=\dfrac{2\left(x+3\right)\left(x-3\right)}{6x\left(x+1\right)\left(x+3\right)}\)

\(g,PT\left(1\right)=\dfrac{4x^2}{2x\left(x+2\right)^3};PT\left(2\right)=\dfrac{\left(x-2\right)\left(x+2\right)}{2x\left(x+2\right)^3}\\ h,PT\left(1\right)=\dfrac{5}{3x\left(x-2\right)\left(x+2\right)}=\dfrac{10\left(x+3\right)}{6x\left(x-2\right)\left(x+2\right)\left(x+3\right)}\\ PT\left(2\right)=\dfrac{3}{2\left(x+2\right)\left(x+3\right)}=\dfrac{9x\left(x-2\right)}{6x\left(x+2\right)\left(x+3\right)\left(x-2\right)}\)

\(=\dfrac{2x^2y^2}{3xy^2}-\dfrac{2ax+3x}{3a}=\dfrac{2x}{3}-\dfrac{2ax+3x}{3a}\)

\(=\dfrac{2xa-2xa-3x}{3a}=\dfrac{-3x}{3a}=-\dfrac{x}{a}\)

\(=\dfrac{5}{3}-\dfrac{5a-6}{3a}=\dfrac{5a-5a+6}{3a}=\dfrac{6}{3a}=\dfrac{2}{a}\)

\(=\dfrac{2x-3a}{2a}+\dfrac{3}{2}=\dfrac{2x-3a+3a}{2a}=\dfrac{2x}{2a}=\dfrac{x}{a}\)

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