Phân tích đa thức thành nhân tử
A) x^3 - 4x^2 - 12x + 27
b) x^3 - 3x^2 - 4x + 12
c) x^4 - 3x^2 + 4
2) Phân tích đa thức thành nhân tử
a) 9x^2 + 6xy + y^2
b) 6x - 9 - x^2
c) x^2 + 4y^2 + 4xy
d) (x-y)^2 - ( x+y)^2
e) (2x - 1)^2 - (x - 1)^2
f) x^3 + y^3 + z^3 - 3xyz
g) x^2 + 5x - 6
i) 5x^2 + 5xy - x - y
h) 7x - 6x^2 - 2
Mng giải nhanh giùm em bài này, em đang cần gấp lắm ạ
em cám ơn :33
Bạn tải ứng dụng PhotoMath về nha. Ứng dụng này sẽ giải toán số chi tiết
a) \(x^3-4x^2-12x+27\)
\(=\left(x^3+27\right)-\left(4x^2+12x\right)\)
\(=\left(x+3\right)\left(x^2-3x+9\right)-4x\left(x+3\right)\)
\(=\left(x+3\right)\left(x^2-7x+9\right)\)
b) \(x^3-3x^2-4x+12\)
\(=x^2\left(x-3\right)-4\left(x-3\right)\)
\(=\left(x^2-4\right)\left(x-3\right)\)
\(=\left(x+2\right)\left(x-2\right)\left(x-3\right)\)
a) \(9x^2+6xy+y^2=\left(3x+y\right)^2\)
b) \(6x-9-x^2=-\left(x-3\right)^2\)
c) \(x^2+4y^2+4xy=\left(2y+x\right)^2\)
d) \(\left(x-y\right)^2-\left(x+y\right)^2\)
\(=\left(x-y+x+y\right)\left(x-y-x-y\right)\)
\(=2x.\left(-2y\right)=-4xy\)
e) \(\left(2x-1\right)^2-\left(x-1\right)^2\)
\(=\left(2x-1-x+1\right)\left(2x-1+x-1\right)\)
\(=x\left(3x-2\right)\)
g) \(x^2+5x-6\)
\(=x^2+6x-x-6\)
\(=x\left(x+6\right)-\left(x+6\right)\)
\(=\left(x-1\right)\left(x-6\right)\)
f) \(x^3+y^3+z^3-3xyz\)
\(=\left(x+y\right)^3-3xy\left(x+y\right)+z^3-3xyz\)
\(=\left(x+y+z\right)^3-3\left(x+y+z\right)\left(x+y\right)z-3xy\left(x+y\right)\)
\(=\left(x+y+z\right)\left[\left(x+y+z\right)^2-3xy-3zx-3zy\right]\)
\(=\left(x+y+z\right)\left[x^2+y^2+z^2-xy-zx-zy\right]\)
i) \(5x^2+5xy-x-y=5x\left(x+y\right)-\left(x+y\right)=\left(5x-1\right)\left(x+y\right)\)
h) \(7x-6x^2-2\)
\(=\left(3x-6x^2\right)-\left(2-4x\right)\)
\(=3x\left(1-2y\right)-2\left(1-2y\right)\)
\(=\left(3x-2\right)\left(1-2y\right)\)
