20x – 5y
e) 4x2y – 8xy2 + 10x2y2 b) 5x(x – 1) – 3x(x – 1) g) 20x2y – 12×3 c) x(x + y) – 6x – 6y h) 8×4 + 12x2y4 – 16x3y4 d) 6×3 – 9×2 k) 4xy2 + 8xyz
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20x – 5y e) 4x2y – 8xy2 + 10x2y2 b) 5x(x – 1) – 3x(x – 1) g) 20x2y – 12×3 c) x(x + y) – 6x – 6y
By Mary
`a)20x-5y=5(4x-y)`
`b)5x(x-1)-3x(x-1)=(x-1)(5x-3x)=2x(x-1)`
`c)x(x+y)-6x-6y=x(x+y)-6(x+y)=(x+y)(x-6)`
`d)6x³-9x²=3x²(2x-3)`
`e)4x²y-8xy²+10x²y²=2xy(2x-4y+5xy)`
`g)20x²y-12x³=4x²(5y-3x)`
`h)8x^4+12x²y^4-16x³y^4=4x²(2x²+3y^4-4xy^4)`
`k)4xy²+8xyz=4xy(y+2z)`
Đáp án:
Giải thích các bước giải:
`a) 20x – 5y`
`= 5(4x-y)`
`b) 5x(x – 1) – 3x(x – 1) `
` = 5x² – 5x – 3x² + 3x`
`= 2x² – 2x`
`=2x(x-1)`
`c) x(x + y) – 6x – 6y `
`= x(x+y) -6(x+y)`
`= (x+y)(x-6)`
`d)6x^3 – 9x^2 `
`= 3x²(2x – 3)`
` e) 4x²y – 8xy² + 10x²y²`
`= 2xy ( 2x – 4y + 5xy)`
` g) 20x²y – 12x³`
`= 4x²(5y-3x)`
` h) 8x^4 + 12x²y^4 – 16x^3y^4`
`= 4x²( 2x² + 3y^4 – 4x²y^4)`
`k) 4xy^2 + 8xyz`
`= 4xy( y + 2z)`