a, -2x^2y căn 7
b, ab^2 căn 63
c, a-1 căn 147a-147
d, y+2 nhân căn [192 nhân (y+2)^3]
a)-2x²y√7
b) 3ab²√7
c) 7(a-1)√3(a-1)
d) 8(y+2)²√3(y+2)
a) -2x^2y√7
b) 3ab^2√7
c) 7(a-1)√(3(a-1))
d) 8(y+2)^2√(3(y+2))
a. \(-2x^2\sqrt{7}\)
b. \(3ab^2\sqrt{7}\)
c. \(7\left(a-1\right)\sqrt{3\left(a-1\right)}\)
d. \(8\left(y+2\right)^2\sqrt{3\left(y+2\right)}\)
a)-2x^2ycăn 7
b) 3ab^2căn 7
c) 7(a-1)căn 3(a-1)
d) 8(y+2)^2căn 3(y+2)
a) -2x^2y
b) 3ab^2
c) 7(a-1) can 3(a-1)
d) 8(y+2)^2 can 3( y+2)
a) Với \(y\le0\), ta có:
\(\sqrt{28x^4y^2}=2\left|x^2\right|\left|y\right|\sqrt{7}=-2x^2y\sqrt{7}\)
b) Với \(a\ge0\), ta có:
\(\sqrt{63a^2b^4}=3\left|a\right|\left|b^2\right|\sqrt{7}=3ab^2\sqrt{7}\)
c) \(\sqrt{147\left(a-1\right)^3}=7\left(a-1\right)\sqrt{3\left(a-1\right)}=7\left(a-1\right)\sqrt{3a-3}\)
d) \(\sqrt{192\left(y+2\right)^5}=8\sqrt{3\left(y+2\right)}\left(y+2\right)^2=8\sqrt{3y+6}\left(y+2\right)^2\)
a) \(2x^2y\sqrt{7}\)
b) \(3a\left|b^2\right|\sqrt{7}=3ab^2\sqrt{7}\)
a, Với y ≤ 0 ta có :
\(\sqrt{28x^4y^2}\) = 2|x2||y|\(\sqrt{7}\) =\(-2x^2y\sqrt{7}\)
b, Với a ≥ 0 ta có :
\(\sqrt{63a^2b^4}=3\left|a\right|\left|b^2\right|\sqrt{7}=3ab^2\sqrt{7}\)
a)-2x²y√7
b) 3ab²√7
c) 7(a-1)√3(a-1)
d) 8(y+2)²√3(y+2)
a, \(\sqrt{28x^4y^2}=\sqrt{\left(2x^2y\right)^2}.7=2x^2y\sqrt{7}=-2x^2y\sqrt{7}\)
b, \(\sqrt{63a^2b^4=\sqrt{ }\left(3ab^2\right)^2.}7=3ab^2.\sqrt{7}=3ab^2\sqrt{7}\)
c,\(\sqrt{147\left(a-1\right)^3}=\sqrt{\left[7\left(a-1\right)\right]^2.3\left(a-1\right)}=7\left(a-1\right)\sqrt{3\left(a-1\right)}\)
d,\(\sqrt{192\left(y+2\right)^5}=\sqrt{\left[8\left(y+2\right)^2\right]^2}.3\left(y+2\right)=8\left(y+2\right)^2\sqrt{3\left(y+2\right)}\)
A-V28x^4 y^2 = -2x^yV7
B-V63a^2 b^4 = 3ab^2V7
C-V147(a-1)^3 = 7(a-)V3(a-1)
D-V192 ( y + 2) ^5 = 8(y+2)^2 V3(y+2)
a)\(\sqrt{28x^1y^2}\) =\(\sqrt{4.7.\left(x^2\right).y^2}\) = \(\sqrt{2^2.7\left(x^2\right).y^2}\) = \(2x^2\left|y\right|\sqrt{7}\) = \(-2x^2y\sqrt{7}\)
b)\(\sqrt{63a^2b^4}\) = \(\sqrt{9.7.a^2\left(b^2\right)^2}=\sqrt{3^2.7.a^2\left(b^2\right)^2}=3\left|a\right|b^2\sqrt{7}=3ab^2\sqrt{7}\)
c) \(\sqrt{147\left(a-1\right)^3}=\sqrt{49.3\left(a-1\right)\left(a-1\right)^2}=\sqrt{7^2.3.\left(a-1\right)\left(a-1\right)^2}=7\left(a-1\right)\sqrt{3\left(a-1\right)}=7\left(a-1\right)\sqrt{3a-3}\) d) \(\sqrt{192\left(y+2\right)^5}=8\sqrt{3\left(y+2\right)}\left(y+2\right)^2=8\sqrt{3y+6}\left(y+2\right)^2\)
a, \(\sqrt{28x^4y^2}\) =\(\sqrt{\left(2x^2y\right)^2.7}\) = 2x2y \(\sqrt{7}\) = - 2x2y\(\sqrt{7}\)
b,\(\sqrt{63a^2b^4}\) =\(\sqrt{\left(3ab^2\right)^2.7}\) = 3ab2 \(\sqrt{7}\) = 3ab2\(\sqrt{7}\)
c, \(\sqrt{147\left(a-1\right)^3}\) =\(\sqrt{\left[7\left(a-1\right)\right]^2.3\left(a-1\right)}\) = 7(a-1)\(\sqrt{3\left(a-1\right)}\)
d, \(\sqrt{192\left(y+2\right)^5}\) = \(\sqrt{\left[8\left(y+2\right)^2\right]^2.3\left(y+2\right)}\) =8(y+2)2\(\sqrt{3\left(y+2\right)}\)
a)\(\sqrt{\left(2x^2y\right)^2.7}\) =I2x2yI.\(\sqrt{7}\)=-2x2y.\(\sqrt{7}\)( với y<=0)
b)\(\sqrt{\left(3ab^2\right)^2}.7\)=I3ab2I.\(\sqrt{7}\)=3ab2.\(\sqrt{7}\)(với a<=0)
c)\(\sqrt{\left[7\left(a-1\right)\right]^2}.3\left(a-1\right)\)=7(a-1).\(\sqrt{3\left(a-1\right)}\)
d)\(\sqrt{\left[8\left(y+2^{ }\right)^2\right]^2.3\left(y+2\right)}\)=8(y+2).\(\sqrt{3\left(y+2\right)}\)\(\sqrt{7}\)\(\sqrt{7}\)
a) \(\sqrt{28^4y^2}=\sqrt{\left(2^2y\right)^2}.7=\left|2x^2y\right|\sqrt{7}=-2x^2y\sqrt{7}\) (vì y ≤ 0)
b) \(\sqrt{63a^2b^4}=\sqrt{\left(3ab^2\right)^2}.7=\left|3ab^2\right|\sqrt{7}=3ab^2\sqrt{7}\) (vì a ≥ 0)
c) \(\sqrt{147\left(a-1\right)^3}=\sqrt{\left[7\left(a-1\right)\right]^2.3\left(a-1\right)}=7\left(a-1\right)\sqrt{3\left(a-1\right)}\)
\(\sqrt{192\left(y+2\right)^5}=\sqrt{\left[8\left(y+2\right)^2\right]^2}.3\left(y+2\right)=8\left(y+2\right)^2\sqrt{3\left(y+2\right)}\)
a, \(\sqrt{28x^4y^2}=\sqrt{\left(2x^2y\right)^2.7}=2x^2y\sqrt{7}=-2x^2y\sqrt{7}\) ( vì y < 0 )
b,\(\sqrt{63a^3b^4}=\sqrt{\left(3ab^2\right)^3.7}=3ab^2\sqrt{7}=3ab^2\sqrt{7}\) (vì a > 0 )
c, \(\sqrt{147\left(a-1\right)^3}=\sqrt{\left[7\left(a-1\right)\right]^2.3\left(a-1\right)}=7\left(a-1\right)\sqrt{3\left(a-1\right)}\)
d, \(\sqrt{192\left(y+2\right)^5}=\sqrt{\left[8\left(y+2\right)^2\right]^2.3\left(y+2\right)}=8\left(y+2\right)^2\sqrt{3\left(y+2\right)}\)
a, Căn 28x^4y^2= căn(2 x^2y)^2.7=|2x^2y| căn 7
= -2x^2y căn 7
b, Căn 63a^2b^4=căn (3ab^2)^2.7=|3ab^2| căn 7=3ab^2 căn 3
c, Căn 149(a-1)^3= căn [7(a-1)]^2.3(a-1)=7(a-1) căn 3(a-1)
d, Căn 192(y+2)^5= căn [8(y+2)^2]^2.3(y+2)
=8(y+2)^2 căn 3(y+2)
a) = 2x\(^2\)y\(\sqrt{7}\)
b) =3ab\(^2\)\(\sqrt{7}\)
c) =\(\sqrt{3\left(a-1\right)}\)
d) =\(\sqrt{3\left(y+2\right)}\)