viết các đa thúc sau thành tích :
a) \(x^3+8y^3\)
b) \(a^6-b^3\)
c) \(8y^3-125\)
d) \(8x^3+27\)
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(27x^3\)\(+\)\(8y^3\)\(=\)\(3^3\times x^3\)\(+\)\(2^3\times y^3\)\(=\)\((3x)^3\)\(+\)\((2y)^3\)\(=\)\((3x+2y)\)\(\times\)\((3^2\times x^2-3x\times2y+2^2\times y^2)\)
Khai triển các tích sau
a) (3x+5)^2 e) 27y^3-8
b) (x^2-4y)^2
c) (8y+1) (8y-1)
d) (2x^3+1)^3
f) 125+27y^3
\(a,x^3+8y^3=\left(x+2y\right)\left(x^2-2xy+4y^2\right)\)
\(b,a^6-b^3=\left(a^2-b\right)\left(a^4+a^2b+b^2\right)\)
\(c,8y^3-125=\left(2y-5\right)\left(4y^2+10y+25\right)\)
\(d,8z^3+27=\left(2z+3\right)\left(4z^2-6z+9\right)\)
\(a)x^3+8y^3=x^3+\left(2y\right)^3=\left(x+2y\right)\left(x^2-2xy+4y^2\right)\)
\(b)a^6-b^3=\left(a^3-b^3\right)\left(a^3+b^3\right)\)
\(c)8y^3-125=\left(2y\right)^3-5^3=\left(2y-5\right)\left(4y^2+10y+25\right)\)
\(d)8z^3+27=\left(2z\right)^3+3^3=\left(2x+3\right)\left(4z^2-6z+9\right)\)
D) 64x^3-1/8y^3
= (4x)^3 + (1/2y)^3
= ( 4x + 1/2y ) [ (4x)^2 - 4x.1/2y + (1/2y)^2 ]
E) 125x^6-27y^9
( câu này mik chưa rõ nên vx chưa tek giải cho bn )
HOk tốt nhé
\(x^3+8y^3\)
\(=x^3+\left(2y\right)^3\)
\(=\left(x+2y\right)\left(x^2-2xy+4y^2\right)\)
\(8y^3-125\)
\(=\left(2y\right)^3-5^3\)
\(=\left(2y-5\right)\left(4y^2+10y+25\right)\)
\(a^6-b^3\)
\(=\left(a^2\right)^3-b^3\)
\(=\left(a^2-b\right)\left(a^4+a^2b+b^2\right)\)
\(8x^3-\frac{1}{8}\)
\(=\left(2x\right)^3-\left(\frac{1}{2}\right)^3\)
\(=\left(2x-\frac{1}{2}\right)\left(4x^2+x+\frac{1}{4}\right)\)
\(x^{32}-1\)
\(=\left(x^{16}\right)^2-1^2\)
\(=\left(x^{16}-1\right)\left(x^{16}+1\right)\)
\(=\left(x^8-1\right)\left(x^8+1\right)\left(x^{16}+1\right)\)
\(=\left(x^4-1\right)\left(x^4+1\right)\left(x^8+1\right)\left(x^{16}+1\right)\)
\(=\left(x^2-1\right)\left(x^2+1\right)\left(x^4+1\right)\left(x^8+1\right)\left(x^{16}+1\right)\)
\(=\left(x-1\right)\left(x+1\right)\left(x^2+1\right)\left(x^4+1\right)\left(x^8+1\right)\left(x^{16}+1\right)\)
Bạn sai đề rồi :
a ) \(8y^3-125\)
\(=\left(2y\right)^3-5^3\)
\(=\left(2y-5\right)\left(4y^2+2y.5+5^2\right)\)
\(=\left(2y-5\right)\left(4y^2+10y+25\right)\)
b) Ta thấy \(8z^3=\left(2z\right)^3\)còn \(27=3^3\)
Trở thành : \(\left(2z\right)^3+3^3\)
Rồi bạn bạn tự làm nha
Thanks
\(x^3+27y^3=x^3+\left(3y\right)^3=\left(x+3y\right)\left(x^2-3xy+9y^2\right)\)
\(a^6-8b^3=\left(a^2\right)^3-\left(2b\right)^3=\left(a^2-2b\right)\left(a^4+2a^2b+4b^2\right)\)
\(8y^3-125=\left(2y\right)^3-5^3=\left(2y-5\right)\left(4y^2+10y+25\right)\)
\(8z^3+x^3=\left(2z\right)^3+x^3=\left(2z+x\right)\left(4z^2-2xz+x^2\right)\)
\(\left(x-1\right)^2-25\)
\(=x^2-2x+1-25\)
\(=x^2-2x-24\)
\(=x^2-6x+4x-24\)
\(=x.\left(x-6\right)+4.\left(x-6\right)\)
\(=\left(x+4\right).\left(x-6\right)\)
a, \(1-2y+y^2=\left(y+1\right)^2=\left(y+1\right)\left(y+1\right)\)
b, \(\left(x+1\right)^2-25=\left(x+1\right)^2-5^2=\left(x+1-5\right)\left(x+1+5\right)=\left(x-4\right)\left(x+6\right)\)
c, \(1-4x^2=1^2-\left(2x\right)^2=\left(1-2x\right)\left(1+2x\right)\)
d, \(8-27x^3=2^3-\left(3x\right)^3=\left(2-3x\right)\left(4+6x+9x^2\right)\)
a) \(x^3+8y^3=x^3+\left(2y\right)^3=\left(2y+x\right)\left(4y^2-2xy+x^2\right)\)
b) \(a^6-b^3=\left(a^2\right)^3-b^3=\left(a^2-b\right)\left(b^2+a^2b+a^4\right)\)
c) \(8y^3-125=\left(2y\right)^3-5^3=\left(2y-5\right)\left(4y^2+10y+25\right)\)
d) \(8x^3+27=\left(2x\right)^3+3^3=\left(2x+3\right)\left(4x^2-6x+9\right)\)
a) x3+8y3x3+8y3
=(x+2y)(x2−2xy+4y2)
b) a6−b3
=(a2)3-b3
=(a2-b) (a4+a2b+b2)
c) 8y3−125
=(2y−5)(4y2+10y+25)
d) 8x3+27
=(2x+3)(4x2−6x+9)
hok tốt!!!