Question

1) Viết biểu thức sau dưới dạng hiệu 2 bình phương:

a)4x²+6x+7-y²-6y

b)x²+y²-4x-6y+13

c)4x²-12x-y²+2y+8

Answer 1

b)   \(x^2+y^2-4x-6y+13\)

\(=\left(x^2-4x+4\right)+\left(y^2-6y+9\right)\)

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

c)  \(4x^2-12x-y^2+2y+8\)

\(=\left(4x^2-12x+9\right)-\left(y^2-2y+1\right)\)

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

Answer 2

\(x^2+y^2-4x-6y+13\)

\(=\left(x^2-4x+4\right)+\left(y^2-6y+9\right)\)

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

hk