Question

3x^{2 -} 2x+ 4

2x²+3x

4x² +2y² +6x - 4y+1

3x² -6x +2

6x² +4y² -7x+ 2y

TÌM MIN (Giúp mik vs )

Answer 1

a: \(=3\left(x^2-\dfrac{2}{3}x+\dfrac{4}{3}\right)\)

\(=3\left(x^2-2\cdot x\cdot\dfrac{1}{3}+\dfrac{1}{9}+\dfrac{11}{9}\right)\)

\(=3\left(x-\dfrac{1}{3}\right)^2+\dfrac{11}{3}>=\dfrac{11}{3}\)

Dấu '=' xảy ra khi x=1/3

b: \(=2\left(x^2+\dfrac{3}{2}x\right)\)

\(=2\left(x^2+2\cdot x\cdot\dfrac{3}{4}+\dfrac{9}{16}-\dfrac{9}{16}\right)\)

\(=2\left(x+\dfrac{3}{4}\right)^2-\dfrac{9}{8}>=-\dfrac{9}{8}\)

Dấu '=' xảy ra khi x=-3/4

d: \(=3\left(x^2-2x+\dfrac{2}{3}\right)\)

\(=3\left(x^2-2x+1-\dfrac{1}{3}\right)\)

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

Dấu '=' xảy ra khi x=1