Nhân ra thôi chứ sao?

thì bạn nhân đi !

các bn ơi , bn nào biến đổi đưa về dạng những hằng đẳng thức cũng được nữa nhá !

bài tập tết nâng cao phải ko

mk cũng có nhưng chưa làm dc

a)\(16x^2-\left(4x-5\right)^2=15\)

\(\Rightarrow\left(4x\right)^2-\left(4x-5\right)^2-15=0\)

\(\Rightarrow\left(4x-4x+5\right)\left(4x+4x-5\right)-15=0\)

\(\Rightarrow5\left(8x-5\right)-15=0\)

\(\Rightarrow40x-25-15=0\)

\(\Rightarrow40x-40=0\)

\(\Rightarrow x=1\)

b)\(\left(2x+3\right)^2-4\left(x-1\right)\left(x+1\right)=49\)

\(\Rightarrow\left(4x^2-12x-9\right)-4\left(x^2-1\right)-49=0\)

\(\Rightarrow4x^2-12x+9-4x^2+4-49=0\)

\(\Rightarrow12x-36=0\)

\(\Rightarrow12\left(x-3\right)=0\)

\(\Rightarrow x=3\)

\(b,\left(x+2\right)\left(x^2-2x+4\right)-x\left(x^2+2\right)=15\)

\(\Leftrightarrow x^3+8-x^3-2x=15\)

\(\Leftrightarrow-2x=15-8=7\)

\(\Leftrightarrow x=\frac{-7}{2}\)

Vậy \(x=\frac{-7}{2}\)

1: \(\Leftrightarrow2x^2-10x-3x-2x^2=0\)

=>-13x=0

=>x=0

2: \(\Leftrightarrow5x-2x^2+2x^2-2x=13\)

=>3x=13

=>x=13/3

3: \(\Leftrightarrow4x^4-6x^3-4x^3+6x^3-2x^2=0\)

=>-2x^2=0

=>x=0

4: \(\Leftrightarrow5x^2-5x-5x^2+7x-10x+14=6\)

=>-8x=6-14=-8

=>x=1

`1)2x(x-5)-(3x+2x^2)=0`

`<=>2x^2-10x-3x-2x^2=0`

`<=>-13x=0`

`<=>x=0`

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`2)x(5-2x)+2x(x-1)=13`

`<=>5x-2x^2+2x^2-2x=13`

`<=>3x=13<=>x=13/3`

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`3)2x^3(2x-3)-x^2(4x^2-6x+2)=0`

`<=>4x^4-6x^3-4x^4+6x^3-2x^2=0`

`<=>x=0`

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`4)5x(x-1)-(x+2)(5x-7)=0`

`<=>5x^2-5x-5x^2+7x-10x+14=0`

`<=>-8x=-14`

`<=>x=7/4`

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`5)6x^2-(2x-3)(3x+2)=1`

`<=>6x^2-6x^2-4x+9x+6=1`

`<=>5x=-5<=>x=-1`

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`6)2x(1-x)+5=9-2x^2`

`<=>2x-2x^2+5=9-2x^2`

`<=>2x=4<=>x=2`