Phân tích đa thức thành nhân tử :
a. \(\sqrt{ax}+\sqrt{by}-\sqrt{ay}-\sqrt{bx}\)
b. \(\sqrt{a^2-b^2}-\sqrt{a^3+b^3}\)
c. \(x-3\sqrt{x}-18\)
d. \(x\sqrt{x}+4x-12\sqrt{x}-27\)
phân tích đa thức thành nhân tử (với a b x y không âm, a> b)
a) xy - \(y\sqrt{x}\) + \(\sqrt{x}-1\)
b) \(\sqrt{ab}-\sqrt{by}+\sqrt{bx}+\sqrt{ay}\)
c) \(\sqrt{a+b}+\sqrt{a^2+b^2}\)
d) 12 - \(\sqrt{x}\) - x
d: \(=-\left(x+\sqrt{x}-12\right)=-\left(\sqrt{x}+4\right)\left(\sqrt{x}-3\right)\)
phân tích đa tức thành nhân tử
a) 5+ \(\sqrt{x}\) + 25 - x
b) xy -x\(\sqrt{y}\) + \(\sqrt{y}\) - 1
c)\(\sqrt{a-b}\) - \(\sqrt{a^2-b^2}\)
d) \(\sqrt{ax}\) + \(\sqrt{by}\) - \(\sqrt{bx}\) -\(\sqrt{ay}\)
Giair hộ mình vs ạ!
Phân tích đa thức thành nhân tử:
a) \(\sqrt{a^2-b^2}\) - \(\sqrt{a^3+b^3}\)
b) x - \(3\sqrt{x}\) - 18
c) \(x\sqrt{x}\) + 4x - \(12\sqrt{x}\) - 27
\(x\sqrt{x}+4x-12\sqrt{x}-27\)
\(=\left(x\sqrt{x}-27\right)+\left(4x-12\sqrt{x}\right)\)
\(=\left(\sqrt{x}-3\right)\left(x+3\sqrt{x}+9\right)+4\sqrt{x}\left(\sqrt{x}-3\right)\)
\(=\left(\sqrt{x}-3\right)\left(x+3\sqrt{x}+9+4\sqrt{x}\right)\)
\(=\left(\sqrt{x}-3\right)\left(x+7\sqrt{x}+9\right)\)
a, \(\sqrt{a^2-b^2}-\sqrt{a^3+b^3}\)
\(=\sqrt{\left(a+b\right)\left(a-b\right)}-\sqrt{\left(a+b\right)\left(a^2-ab+b^2\right)}\)
\(=\sqrt{a+b}\left(\sqrt{a-b}-\sqrt{a^2-ab+b^2}\right)\)
\(x-3\sqrt{x}-18\)
\(=x+3\sqrt{x}-6\sqrt{x}-18\)
\(=\sqrt{x}\left(\sqrt{x}+3\right)-6\left(\sqrt{x}+3\right)\)
\(=\left(\sqrt{x}+3\right)\left(\sqrt{x}-6\right)\)
Phân tích thành nhân tử ( với các số x, y, a, b không âm và \(a\ge b\))
a) \(xy-y\sqrt{x}+\sqrt{x}-1\)
b) \(\sqrt{ax}-\sqrt{by}+\sqrt{bx}-\sqrt{ay}\)
c) \(\sqrt{a+b}+\sqrt{a^2-b^2}\)
d) \(12-\sqrt{x}-x\)
\(a)\) \(xy-y\sqrt{x}+\sqrt{x}-1\)
= \(y\sqrt{x}.(\sqrt{x}-1)+\sqrt{x}-1\)
=\((\sqrt{x}-1).(y\sqrt{x}+1)\).
\(b)\)\(\sqrt{ax}-\sqrt{by}+\sqrt{bx}-\sqrt{ay}\)
=\(\sqrt{a}.\sqrt{x}-\sqrt{b}.\sqrt{y}+\sqrt{b}.\sqrt{x}-\sqrt{a}.\sqrt{y}\)
=\(\sqrt{a}.\sqrt{x}+\sqrt{b}.\sqrt{x}-\sqrt{a}.\sqrt{y}-\sqrt{b}.\sqrt{y}\)
=\(\sqrt{x}.(\sqrt{a}+\sqrt{b})-\sqrt{y}.(\sqrt{a}+\sqrt{b})\)
=\((\sqrt{x}-\sqrt{y}).(\sqrt{a}+\sqrt{b})\).
\(c)\)\(\sqrt{a+b}+\sqrt{a^2-b^2}\)
=\(\sqrt{a+b}+\sqrt{(a+b).(a-b)}\)
=\(\sqrt{a+b}+\sqrt{a+b}.\sqrt{a-b}\)
=\(\sqrt{a+b}.\left(1+\sqrt{a-b}\right)\).
\(d)\) \(12-\sqrt{x}-x\)
=\(12-4\sqrt{x}+3\sqrt{x}-x\)
=\(4.\left(3-\sqrt{x}\right)+\sqrt{x}\left(3-\sqrt{x}\right)\)
=\(\left(3-\sqrt{x}\right).\left(4+\sqrt{3}\right)\).
a) \(xy-y\sqrt{x}+\sqrt{x}-1=\left(\sqrt{x}\right)^2.y-y\sqrt{x}+\sqrt{x}-1\)
\(=y\sqrt{x}\left(\sqrt{x}-1\right)+\left(\sqrt{x}-1\right)\)
\(=\left(\sqrt{x}-1\right)\left(y\sqrt{x}+1\right)\)
b) \(\sqrt{ax}-\sqrt{by}+\sqrt{bx}-\sqrt{ay}=\left(\sqrt{ax}+\sqrt{bx}\right)-\left(\sqrt{ay}+\sqrt{by}\right)\)
\(=\sqrt{x}\left(\sqrt{a}+\sqrt{b}\right)-\sqrt{y}\left(\sqrt{a}+\sqrt{b}\right)\)
\(=\left(\sqrt{a}+\sqrt{b}\right)\left(\sqrt{x}-\sqrt{y}\right)\)
c) \(\sqrt{a+b}+\sqrt{a^2-b^2}=\sqrt{a+b}+\sqrt{\left(a-b\right)\left(a+b\right)}\)
\(=\sqrt{a+b}+\sqrt{a-b}.\sqrt{a+b}\)
\(=\sqrt{a+b}.\left(1+\sqrt{a-b}\right)\)
d) \(12-\sqrt{x}-x=12-\sqrt{4x}+\sqrt{3x}-x\)
\(=4\left(3-\sqrt{x}\right)+\sqrt{x}\left(3-\sqrt{x}\right)\)
\(=\left(3-\sqrt{x}\right)\left(4+\sqrt{x}\right)\)
Phân tích đa thức thành nhân tử (với các căn thức đã cho đều có nghĩa)
A = \(x-y-3\left(\sqrt{x}+\sqrt{y}\right)\)
B = \(x-4\sqrt{x}+4\)
C = \(\sqrt{x^3}-\sqrt{y^3}+\sqrt{x^2y}-\sqrt{xy^2}\)
D = \(5x^2-7x\sqrt{y}+2y\)
Phân tích thành nhân tử
a) \(\sqrt{a^3+b^3}+\sqrt{a^2-b^2}\)
b)\(\sqrt{ax}-\sqrt{by}+\sqrt{bx}-\sqrt{xy}\)
c) \(\sqrt{x^3}-\sqrt{y^3}+\sqrt{x^2y}-\sqrt{xy^2}\)
d) \(a+5\sqrt{a}+4\)
\(\text{a) }\sqrt{a^3+b^3}+\sqrt{a^2-b^2}=\sqrt{\left(a+b\right)\left(a^2-ab+b^2\right)}+\sqrt{\left(a+b\right)\left(a-b\right)}\)
\(=\sqrt{a+b}\left(\sqrt{a^2-ab+b^2}+\sqrt{a-b}\right)\)
\(\text{b) }\sqrt{ax}-\sqrt{by}+\sqrt{bx}-\sqrt{xy}\text{ không phân tích được.}\)
\(\text{c) }=\left(\sqrt{x}-\sqrt{y}\right)\left(x+\sqrt{xy}+y\right)+\left(\sqrt{x}-\sqrt{y}\right).\sqrt{xy}\)
\(=\left(\sqrt{x}-\sqrt{y}\right)\left(x+y+2\sqrt{xy}\right)\)\(=\left(\sqrt{x}-\sqrt{y}\right)\left(\sqrt{x}+\sqrt{y}\right)^2\)
\(\text{d) }a+5\sqrt{a}+4=\sqrt{a}.\sqrt{a}+\sqrt{a}+4\sqrt{a}+4=\sqrt{a}\left(\sqrt{a}+1\right)+4\left(\sqrt{a}+1\right)\)
\(=\left(\sqrt{a}+1\right)\left(\sqrt{a}+4\right)\)
Phân tích thành nhân tử:
a) \(xy-y\sqrt{x}+\sqrt{x}-1\)
b) \(\sqrt{ax}-\sqrt{by}+\sqrt{bx}-\sqrt{ay}\)
a> = \(y\sqrt{x}\left(\sqrt{x}-1\right)+\left(\sqrt{x}-1\right)=\left(\sqrt{x}-1\right)\left(y\sqrt{x}-1\right)\)
a) \(xy-y\sqrt{x}+\sqrt{x}-1\)
\(=y\sqrt{x}\left(\sqrt{x}-1\right)+\left(\sqrt{x}-1\right)\)
\(=\left(\sqrt{x}-1\right)\left(y\sqrt{x}+1\right)\)
b) \(\sqrt{ax}-\sqrt{by}+\sqrt{bx}-\sqrt{ay}\)
\(=\left(\sqrt{ax}-\sqrt{ay}\right)+\left(-\sqrt{by}+\sqrt{bx}\right)\)
\(=\sqrt{a}.\left(\sqrt{x}-\sqrt{y}\right)+\sqrt{b}.\left(\sqrt{x}-\sqrt{y}\right)\)
\(=\left(\sqrt{x}-\sqrt{y}\right)\left(\sqrt{a}+\sqrt{b}\right)\)
Phân tích đa thức thành nhân tử (với các căn thức đều đã có nghĩa):
a) A = \(\sqrt{x^3}\) - \(\sqrt{y^3}\) + \(\sqrt{x^2y}\) - \(\sqrt{xy^2}\)
b) B = 5x2 - 7x\(\sqrt{y}\) + 2y
a: \(A=x\sqrt{x}-y\sqrt{y}+x\sqrt{y}-y\sqrt{x}\)
\(=\left(\sqrt{x}-\sqrt{y}\right)\left(x+\sqrt{xy}+y\right)+\sqrt{xy}\left(\sqrt{x}-\sqrt{y}\right)\)
\(=\left(\sqrt{x}-\sqrt{y}\right)\left(\sqrt{x}+\sqrt{y}\right)^2\)
b: \(B=5x^2-7x\sqrt{y}+2y\)
\(=5x^2-5x\sqrt{y}-2x\sqrt{y}+2y\)
\(=5x\left(x-\sqrt{y}\right)-2\sqrt{y}\left(x-\sqrt{y}\right)\)
\(=\left(x-\sqrt{y}\right)\left(5x-2\sqrt{y}\right)\)
Phân tích biểu thức sau về dạng nhân tử:
a) \(\sqrt{ax}-\sqrt{by}+\sqrt{bx}-\sqrt{ay}\)
b) \(x^2+x\sqrt{x}+\sqrt{x}+1\)
c) \(\sqrt{6.x}-x.2\sqrt{3}\)
a, \(\sqrt{ax}-\sqrt{by}+\sqrt{bx}-\sqrt{ay}\)
\(=\sqrt{x}\left(\sqrt{a}+\sqrt{b}\right)-\sqrt{y}\left(\sqrt{a}+\sqrt{b}\right)\)
\(=\left(\sqrt{x}-\sqrt{y}\right)\left(\sqrt{a}+\sqrt{b}\right)\)
b, \(x^2+x\sqrt{x}+\sqrt{x}+1\)
\(=\sqrt{x}\left(x\sqrt{x}+1\right)+\left(x\sqrt{x}+1\right)\)
\(=\left(\sqrt{x}+1\right)\left(x\sqrt{x}+1\right)\)
c, \(\sqrt{6x}-x2\sqrt{3}\)
\(=\sqrt{6x}-\sqrt{12x^2}\)
\(=\sqrt{6x}\left(1-\sqrt{2x}\right)\)