Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Làm bài 1 thôi !! Mấy bài kia tương tự . Tìm nhân tử chung ra .
a) \(m^2-n^2=\left(m-n\right)\left(m+n\right)\)
b) \(\left(x^2+x-1\right)^2-\left(x^2+2x+3\right)^2=\left(x^2+x-1+x^2+2x+3\right)\left(x^2+x-1-x^2-2x-3\right)\)
\(=\left(2x^2+3x+2\right)\left(-x-4\right)\)
c) \(-16+\left(x-3\right)^2=\left(x-3+4\right)\left(x-3-4\right)=x\left(x-7\right)\)
d) \(64+16y+y^2=\left(y+8\right)\left(y+8\right)\)
a) = (3x)^2 + 2.3x.5+ 5^2 = (3x+5)^2
b) = (2/3x)^2-(4y)^2=(2/3x-4y)(2/3x+4y)
c) = -(9x^4-12/5x^2y^2+4/25y^4) = -[(3x^2)^2 - 2.3x^2.2/5y^2 + (2/5y^2)^2]= -(3x^2-2/5y^2)^2
d) = (x-5)^2 - 4^2= (x-5+4)(x-5-4) = (x-1)(x-9)
e) = (2x)^3 + 3.(2x)^2.(5y) + 3.(2x).(5y)^2 + (5y)^3 = (2x+5y)^3
f) = (8x)^2 - (8a+b)^2 = (8x-8a-b)(8x+8a+b)
g) = (7x-4-2x-1)(7x-4+2x+1) = (5x-5)(9x-3) = 5(x-1).3(x-3)=15(x-1)(x-3)
h) = (x-y)(x+y)- 2(x+y) = (x+y)(x-y-2)
# Chúc bạn học tốt #
a)x2-4y2
=x2-(2y)2
=(x-2y)(x+2y)
b)x3+27y3
=x3+(3y)3
=(x+3y)(x2-3xy+9y2)
c)4x2+12xy+9y2-16
=(2x+3y)2-42
=(2x+3y-4)(2x+3y+4)
d)9x2-24xy+16y2-64
=(3x-4y)2-82
=(3x-4y-8)(3x-4y+8)
e)8x3-27y3
=(2x)3-(3y)3
=(2x-3y)(4x2+6xy+9y2)
f)5x3-7x2+10x-14
=5x3+10x-7x2-14
=5x(x2+2)-7(x2+2)
=(5x-7)(x2+2)
b) \(-y^8+10y^4x^3-25x^6\)
\(=-\left(y^8-10y^4x^3+25x^6\right)\)
\(=-\left[\left(y^4\right)^2-2.y^4.5x^3+\left(5x^3\right)^2\right]\)
\(=-\left(y^4-5x^3\right)^2\)
c) \(8x^3+36x^2y+54xy^2+27y^3\)
\(=\left(2x\right)^3+3.\left(2x\right)^2.3y+3.2x.\left(3y\right)^2+\left(3y\right)^3\)
\(=\left(2x+3y\right)^3\)
d) \(-y^3+12y^2x-48yx^2+64x^3\)
\(=-\left(y^3-12y^2x+48yx^2-64x^3\right)\)
\(=-\left[y^3-3.y^2.4x+3.y.\left(4x\right)^2-\left(4x\right)^3\right]\)
\(=-\left(y-4x\right)^3\)
e) \(64x^6y^4-81x^2y^2\)
\(=\left(8x^3y^2\right)^2-\left(9xy\right)^2\)
\(=\left(8x^3y^2-9xy\right)\left(8x^3y^2+9xy\right)\)
f) \(64x^6-27y^6\)
\(=\left(4x^2\right)^3-\left(3y^2\right)^3\)
\(=\left(4x^2-3y^2\right)\left[\left(4x^2\right)^2+4x^2.3y^2+\left(3y^2\right)^2\right]\)
\(=\left(4x^2-3y^2\right)\left(16x^4+12x^2y^2+9x^4\right)\)
a)\(x^3+3xy+y^3-1\)
\(=x^3+3x^2y+3xy^2+y^3-1-3x^2y-3xy^2+3xy\)
\(=\left(x+y\right)^3-1^3-3xy\left(x+y-1\right)\)
\(=\left(x+y-1\right)\left(x^2+2xy+y^2+x+y+1\right)-3xy\left(x+y-1\right)\)
\(=\left(x+y-1\right)\left(x^2+2xy+y^2+x+y+1-3xy\right)\)
\(=\left(x+y-1\right)\left(x^2-xy+y^2+x+y+1\right)\)
b) Đặt \(B=3x^2+22xy+11x+37y+7y^2+10\)
Giả sử \(B=\left(ax+by+c\right)\left(mx+ny+p\right)\)
\(=amx^2+anxy+apx+bmxy+bny^2+bpy+cmx+cny+cp\)
\(=amx^2+\left(an+bm\right)xy+\left(ap+cm\right)x+bny^2+\left(bp+cn\right)y+cp\)
Ta được hệ: \(\left\{{}\begin{matrix}am=3;an+bm=22\\ap+cm=11;bn=7\\bp+cn=37;cp=10\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}a=3;b=1\\c=5;m=1\\n=7;p=2\end{matrix}\right.\)
Vậy B phân tích được thành \(\left(3x+y+5\right)\left(x+7y+2\right)\).
a/ =(x+y)3-1-3xy(x+y-1)
=(x+y-1)(x2+2xy+y2+xy+1)-3xy(x+y-1)
=(x+y-1)(x2+y2+1)
mơn nha
Đề là gì bạn nhỉ?
\(16-\left(x-3\right)^2=4^2-\left(x-3\right)^2=\left(4-x-3\right)\left(4+x-3\right)\)
\(64+16y+y^2=y^2+2y4+4^2=\left(y+4\right)^2\)
\(1,24^2-0,24^2=\left(1,24-0,24\right)\left(1,24+0,24\right)=1.1,48=1,48\)
\(\frac{1}{8}-8x^3=\left(\frac{1}{2}\right)^3-\left(2x\right)^3=\left(\frac{1}{2}-2x\right)\left(\frac{1}{4}+x+4x^2\right)\)
\(100-\left(3x-y\right)^2=10^2-\left(3x-y\right)=\left(10-3x+y\right)\left(10+3x-y\right)\)
\(64x^2-\left(8x+3\right)^2\)
\(=\left(8x\right)^2-\left(8x+3\right)^2\)
\(=\left(8x-8x-3\right)\left(8x+8x+3\right)\)
\(=\left(-3\right)\left(16x+3\right)\)
\(=-48x-9\)