Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a) \(\left(2x^2-1\right)^2\)
\(=4x^4-4x^2+1\)
b)\(\left(\dfrac{1}{2}x+3y^2\right)^2\)
\(=\dfrac{1}{4}x^2+3xy^2+9y^4\)
a) \(\left(2x^2-1\right)^2=\left(2x^2\right)^2-2.2x^2.1+1^2\)
\(=4x^4-4x^2+1\).
b) \(\left(\frac{1}{2}x+3y^2\right)^2=\left(\frac{1}{2}x\right)^2+2.\frac{1}{2}x.3y^2+\left(3y^2\right)^2\)
\(=\frac{1}{4}x^2+3y^2x+9y^4\)
Chúc bn hc tốt!
a,\(\left(2x-1\right)\left(4x^2+2x+1\right)=\left(2x-1\right)\left[\left(2x\right)^2+2x.1+1^2\right]\)
\(=\left(2x\right)^3-1=8x^3-1\)
b,\(\left(x+2y+z\right)\left(x+2y-z\right)=\left(x+2y\right)^2-z^2\)
\(=x^2+2.x.2y+\left(2y\right)^2-z^2=x^2+4xy+4y^2-z^2\)
`a)(2x-1)(4x^2+2x+1)`
`=(2x-1)[(2x)^2+2x.1+1^2]`
`=(2x)^3-1^3`
`=8x^3-1`
Áp dụng HĐT:`A^3-B^3=(A-B)(A^2+AB+B^2)`
`b)(x+2y+z)(x+2y-z)`
`=[(x+2y)+z][(x+2y)-z]`
`=(x+2y)^2-z^2`
`=x^2+2.x.2y+(2y)^2-z^2`
`=x^2+4xy+4y^2-z^2`
Áp dụng HĐT:`A^2-B^2=(A+B)(A-B)`
`(A+B)^2=A^2+2AB+B^2`
a) \(\left(2x-1\right)\left(4x^2+2x+1\right)=8x^3-1\)
b) \(\left(x+2y+z\right)\left(x+2y-z\right)=\left(x+2y\right)^2-z^2\)
\(a.\left(2xy-3\right)^2=4x^2y^2-12xy+9\)
\(b.\left(\dfrac{1}{2}x+\dfrac{1}{3}\right)^2=\dfrac{1}{4}x^2+\dfrac{1}{3}x+\dfrac{1}{9}\)
a\(=\frac{1}{4}x^2+2.\frac{1}{2}x.1+1=\frac{1}{4}x^2+x+1\)
b\(=4x^2-2.2x.\frac{1}{3}+\frac{1}{9}=4x^2-\frac{4}{3}x+\frac{1}{9}\)
Bạn học tốt nha >>>>>>
nha
a/\(\left(\frac{1}{2}x+1\right)^2=\frac{1}{4}x^2+x+1^2\)
b/\(\left(2x-\frac{1}{3}\right)^3=8x^3-2x+\frac{2}{3}x-\frac{1}{27}\)
k nha
Giải:
a) \(\left(2x+y+3\right)^2\)
\(=\left(2x+y\right)^2+2.3\left(2x+y\right)+3^2\)
\(=\left(2x\right)^2+2.2x.y+y^2+2.3\left(2x+y\right)+3^2\)
\(=4x^2+4xy+y^2+12x+6y+9\)
Vậy ...
b) \(\left(x-2y+1\right)^2\)
\(=\left(x-2y\right)^2+2\left(x-2y\right)+1^2\)
\(=x^2-2.x.2y+\left(2y\right)^2+2x-4y+1^2\)
\(=x^2-4xy+4y^2+2x-4y+1\)
Vậy ...
c) \(\left(x^2-2xy^2-3\right)^2\)
\(=\left(x^2-2xy^2\right)^2+2.3.\left(x^2-2xy^2\right)-3^2\)
\(=\left(x^2\right)^2-2.x^2.2xy^2+\left(2xy^2\right)^2+2.3.\left(x^2-2xy^2\right)-3^2\)
\(=x^4-4x^3y^2+4x^2y^4+6x^2-12xy^2-9\)
Vậy ...
) (2�+1)2=4�2+4�+1(2x+1)2=4x2+4x+1.
b) (�−�2)3=�3−3�2.�2+3�(�2)2−(�2)3(a−2b)3=a3−3a2.2b+3a(2b)2−(2b)3
=�3−32�2�+34��2−18�3=a3−23a2b+43ab2−81b3.
a) (2�+1)2=4�2+4�+1(2x+1)2=4x2+4x+1.
b) (�−�2)3=�3−3�2.�2+3�(�2)2−(�2)3(a−2b)3=a3−3a2.2b+3a(2b)2−(2b)3
=�3−32�2�+34��2−18�3=a3−23a2b+43ab2−81b3
a) (2�+1)2=4�2+4�+1(2x+1)2=4x2+4x+1.
b) (�−�2)3=�3−3�2.�2+3�(�2)2−(�2)3(a−2b)3=a3−3a2.2b+3a(2b)2−(2b)3
=�3−32�2�+34��2−18�3=a3−23a2b+43ab2−81b3.
a) (2x+1)2=4x2+4x+1(2x+1)2=4x2+4x+1.
b) (a−b2)3=a3−3a2.b2+3a(b2)2−(b2)3(a−2b)3=a3−3a2.2b+3a(2b)2−(2b)3
=a3−32a2b+34ab2−18b3=a3−23a2b+43ab2−81b3.
a) (2x+1)2=4x2+4x+1(2x+1)2=4x2+4x+1.
b) (a−b2)3=a3−3a2.b2+3a(b2)2−(b2)3(a−2b)3=a3−3a2.2b+3a(2b)2−(2b)3
=a3−32a2b+34ab2−18b3=a3−23a2b+43ab2−81b3.
a) (2�+1)2=4�2+4�+1(2x+1)2=4x2+4x+1.
b) (�−�2)3=�3−3�2.�2+3�(�2)2−(�2)3(a−2b)3=a3−3a2.2b+3a(2b)2−(2b)3
=�3−32�2�+34��2−18�3=a3−23a2b+43ab2−81b3.
a) (2�+1)2=4�2+4�+1(2x+1)2=4x2+4x+1.
b) (�−�2)3=�3−3�2.�2+3�(�2)2−(�2)3(a−2b)3=a3−3a2.2b+3a(2b)2−(2b)3
=�3−32�2�+34��2−18�3=a3−23a2b+43ab2−81b3.
a, (2x +1)^2= 2x^2 + 2×2x×1+1^2
=(2x)^2 + 4x + 1
a)
(2x+1)² =(2x)² +2.2x.1+1²= 4x² +4x+1=4x²+4x+1
b)
a-b)³=a³ -3a²
a, 2x^2 + 2* 2x*1+1^2
b,