phân tích thành nhân tử( phối hợp)
1) -12x^3y+74 xy^3
2) 8a^2xy-18b^2xy
3) 9xy-4a^2xy
4) 2xm^3-2x
5) 8a^3x-27b^3x
6) 16a^3xy-54b^3xy
phân tích thành nhân tử( phối hợp)
1) -12x^3y+74 xy^3
2) 8a^2xy-18b^2xy
3) 9xy-4a^2xy
4) 2xm^3-2x
5) 8a^3x-27b^3x
6) 16a^3xy-54b^3xy
Đáp án:
Giải thích các bước giải:
1) -12x³y+74xy³ = -2xy(6x²-37y²)
2) 8a²xy-18b²xy = 2xy(4a²-9b²) = 2xy(2a-3b)(2a+3b)
3) 9xy-4a²xy = xy(9-4a²) = xy(3-2a)(3+2a)
4) 2xm³-2x = 2x(m³-1) = 2x(m-1)(m²+m+1)
5) 8a³x-27b³x = x(8a³-27b³) = x(2a-3b)(4a²+6ab+9b²)
6) 16a³xy-54b³xy = 2xy(8a³-27b³) = 2xy(2a-3b)(4a²+6ab+9b²)
Chúc học tốt!
`1) -12x^3y+74 xy^3`
`=-2xy(6x^2-37y^2)`
`=-2xy[(\sqrt{6}x)^2-(\sqrt{37}y)^2]`
`=-2xy(\sqrt{6}x-\sqrt{7}y)(\sqrt{6}x+\sqrt{7}y).`
`2) 8a^2xy-18b^2xy`
`=2xy(4a^2-9b^2)`
`=2xy[(2a)^2-(3b)^2]`
`=2xy(2a-3b)(2a+3b).`
`3) 9xy-4a^2xy`
`=xy(9-4a^2)`
`=xy[3^2-(2a)^2]`
`=xy(3-2a)(3+2a).`
`4) 2xm^3-2x`
`=2x(m^3-1)`
`=2x(m−1)(m^2+m+1).`
`5) 8a^3x-27b^3x`
`=x(8a^3-27b^3)`
`=x[(2a)^3-(3b)^3]`
`=x(2a−3b)(4a^2+6ab+9b^2).`
`6) 16a^3xy-54b^3xy`
`=2xy(8a^3-27b^3)`
`=2xy.[(2a)^3-(3b)^3]`
`=2xy(2x−3b)(4a^2+6ab+9b^2).`