Question

[Hoàng thị Hiền]

a) x^2 + 20x + 100
b) x^2 - 20xy + 100y^2
c) x^2 - 20x + 100

Answer 1

[Đức Hiếu]

a, \(x^2+20x+100\)

\(=x^2+10x+10x+100\)

\(=x.\left(x+10\right)+10.\left(x+10\right)=\left(x+10\right)^2\)

b, \(x^2-20xy+100y^2\)

\(=x^2-10xy-10xy+100y^2\)

\(=x.\left(x-10y\right)-10y.\left(x-10y\right)=\left(x-10y\right)^2\)

c, \(x^2-20x+100\)

\(=x^2-10x-10x+100\)

\(=x.\left(x-10\right)-10.\left(x-10\right)=\left(x-10\right)^2\)

Chúc bạn học tốt!!!

Answer 2

[Tài Nguyễn Tuấn]

a) $x^2+20x+100=x^2=2.10x+10^2=(x+10)^2$

b) $x^2-20xy+100y^2=x^2-2.x.10y+(10y)^2=(x+10y)^2$

c) $x^2-20x+100=x^2-2.10x+10^2=(x-10)^2$