A=x²+y²+2x-4y+5

 =x²+2x+1+y²-4y+4

=(x+1)²+(y-2)²

A=0

=>(x+1)²+(y-2)²=0

<=>x+1=0 và y-2=0

<=>x=-1 và y=2

\(2xy^2+x^2y^4+1\\ =\left(xy^2\right)^2+2xy^2.1+1^2\\ =\left(xy^2+1\right)^2\)

Ta có :

\(2xy^2+x^2y^4+1=\left(xy^2\right)^2+2.xy^2.1+1^2\)

\(=\left(xy^2+1\right)^2\)

1. 2xy² +x²y⁴+1 = (xy²+1)²

2. a)3x²+3x-10x-10=3x(x+1)-10(x+1)=(x+1)(3x-10)

b)2x²-5x-7=2x²+2x-7x-7=2x(x+1)-7(x+1)=(x+1)(2x-7)

Mong có thể giúp được bạn

x² - 3x + 2
= x² - x - 2x + 2
= x(x - 1) - 2(x - 1)
= (x - 1)(x - 2)

3x² - 7x - 10
= 3x² + 3x - 10x - 10
= 3x(x + 1) - 10(x + 1)
= (x + 1)(3x - 10)

2x² - 5x - 7
= 2x² + 2x - 7x - 7
= 2x(x + 1) - 7(x + 1)
= (x + 1)(2x - 7)

a, \(4x^2+4xy+y^2=\left(4x\right)^2+2.2x.y+y^2\)

\(=\left(4x+y\right)^2\)

b, \(9m^2+n^2-6mn=\left(3m\right)^2-2.3m.n+n^2\)

\(=\left(3m-n\right)^2\)

c, \(16a^2+25b^2+40ab=\left(4a\right)^2+2.4a.5b+\left(5b\right)^2\)

\(=\left(4a+5b\right)^2\)

d, \(x^2-x+\dfrac{1}{4}=x^2-2.x.\dfrac{1}{2}+\left(\dfrac{1}{2}\right)^2\)

\(=\left(x-\dfrac{1}{2}\right)^2\)

Chúc bạn học tốt!!!

cam on ban rat nhieu lan sau nho giup mk nua nha

a) \(x^2+10x+26+y^2+2y\)

= \(x^2+10x+25+y^2+2y+1\)

= \(\left(x+5\right)^2+\left(y+1\right)^2\)

b) \(x^2-2xy+2y^2+2y+1\)

= \(x^2-2xy+y^2+y^2+2y+1\)

= \(\left(x-y\right)^2+\left(y+1\right)^2\)

c) \(z^2-6z+5-t^2-4t\)

= \(z^2-6z+9-\left(t^2+4t+4\right)\)

= \(\left(z-3\right)^2-\left(t+2\right)^2\)

d) \(4x^2-12x-y^2+2y+1\)

Hình như câu này sai đề -_-

a, \(x^2+10x+26+y^2+2y\)

\(=\left(x^2+2.x.5+5^2\right)+\left(1^2+2.1.y+y^2\right)\)

\(=\left(x+5\right)^2+\left(y+1\right)^2\)

b, \(x^2-2xy+2y^2+2y+1\)

\(=x^2-2xy+y^2+y^2+2y+1\)

\(=\left(x^2-2.x.y+y^2\right)+\left(y^2+2.y.1+1^2\right)\)

\(=\left(x-y\right)^2+\left(y+1\right)^2\)

c,\(z^2 -6z+5-t^2-4t\)

\(=-\left(t^2+4t-z^2+6z-5\right)\)

\(=-\left(t^2+2.t.2+2^2-z^2+2.z.3-3^2\right)\)

\(=-\left(\left(t^2+2.t.2+2^2\right)-\left(z^2-2.z.3+3^2\right)\right)\)

\(=-\left(\left(t+2\right)^2-\left(z-3\right)^2\right)\)

\(=\left(z-3\right)^2-\left(t+2\right)^2\)

d, Không biết làm hihi :)

\(\text{Sơn rút ra được hđt là: }\left(a-b\right)^2=\left(b-a\right)^2\)

thank you