Question

[Lương Thùy Linh]

Cho các hằng đẳng thức:

\(1,\left(a+b\right)^2=a^2+2ab+b^2\)

\(2,\left(a-b\right)^2=a^2-2ab+b^2\)

\(3,a^2-b^2=\left(a+b\right)\left(a-b\right)\)

\(4,\left(a+b\right)^3=a^3+3a^2b+3ab^2+b^3\)

\(5,\left(a-b\right)^3=a^3-3a^2b+3ab^2-b^3\)

\(6,a^3+b^3=\left(a+b\right)\left(a^2-ab+b^2\right)\)

\(7,a^3-b^3=\left(a-b\right)\left(a^2+ab+b^2\right)\)

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Điền vào ....

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

\(b,9x^2+y^2+6xy=.............................\)
\(c,25a^2+4b^2-20ab=.............................\)

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

\(e,\left(2x+3y\right)^2+2\left(2x+3x\right)+1=..................\)

\(f,2xy^2+x^2y^4=...........................\)

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

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

Answer 1

[Không Tên]

a)   \(x^2+2x+1=\left(x+1\right)^2\)

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

c)   \(25a^2+4b^2-20ab=\left(5a-2b\right)^2\)

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

e)   \(\left(2x+3y\right)^3+2\left(2x+3y\right)+1=\left(2x+3y+1\right)^2\)

f) mk chỉnh lại đề nha:

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

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

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

Answer 2

[Lương Thùy Linh]

cảm ơn bn nha!