Question

[Nguyễn Phương Linh]

Giúp mik nhanh với ạ. Bỏ bài 17 đi nha!!

Answer 1

[nguyen thi oanh]

16.

a) \(x^2+2x+1\)

\(=x^2+2.x.1+1^2\)

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

b) \(9x^2+y^2+6xy\)

\(=9x^2+6xy+y^2\)

\(=\left(3x\right)^2+2.3x.y+y^2\)

\(=\left(3x+y\right)^2\)

c) \(25a^2+4b^2-20ab\)

\(=25a^2-20ab+4b^2\)

\(=\left(5a\right)^2-2.5a.2b+\left(2b\right)^2\)

\(=\left(5a-2b\right)^2\)

d) \(x^2-x+\frac{1}{4}\)

\(=x^2-2.x.\frac{1}{2}+\left(\frac{1}{2}\right)^2\)

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

18. 

a) \(x^2+6xy+...=\left(...+3y\right)^2\)

\(x^2+6xy+9y^2=\left(x+3y\right)^2\)

b) \(...-10xy+25y^2=\left(...-...\right)^2\)

\(x^2-10xy+25y^2=\left(x-5y\right)^2\)