\(B=2\left(x^2-2x+1\right)+\left(y^2-14y+49\right)-35\\ =2\left(x-1\right)^2+\left(y-7\right)^2-35\ge-35\)

dấu = xảy ra khi x=1,y=7

tick mik nha

Ta có: \(B=2x^2-4x+y^2-14y+16\)

\(=2\left(x^2-2x+1\right)+y^2-14y+49-34\)

\(=2\left(x-1\right)^2+\left(y-7\right)^2-34\ge-34\forall x,y\)

Dấu '=' xảy ra khi x=1 và y=7

a,(5x-1)⁶=3⁶

5x-1=3

x=4/5

b,(2x+1)³=0,1³

2x+1=0,1

x=-0,45

c,(2x-3)⁴=(2x-3)⁴(2x-3)²

(2x-3)²=0

2x-3=0

x=3/2

d,(2x+1)⁵=(2x+1)⁵(2x+1)²⁰⁰⁵

(2x+1)²⁰⁰⁵=0

2x+1=0

x=-1/2

\(\Leftrightarrow\left(2x+3-2x+5\right)^2=x^2+6x+64\)

=>x^2+6x=0

=>x(x+6)=0

=>x=0 hoặc x=-6

ta co (2x-1)(3x+1)+(3x+4)(3-2x)=5

     (=)6x²-3x+2x-1+6x-6x²+12-8x=5

     (=)-4x+11=5

     (=)-4x=-6

     (=)x=3/2

(2x-1)(3x+1)+(3x-4)(3-2x)=5

<=> 6x²+2x-3x-1+9x-6x²-12+8x=5

<=> 16x-13=5

<=> 16x = 18

<=> x=9/8

\(\Leftrightarrow\dfrac{7^x.7^2+7^x.7+7^x}{57}=\dfrac{5^{2x}+5^{2x}.5+5^{2x}.5^3}{131}\)

\(\Leftrightarrow7^x\left(\dfrac{7^2+7+1}{57}\right)=5^{2x}\left(\dfrac{1+5+5^3}{131}\right)\)

\(\Leftrightarrow7^x\dfrac{57}{57}=5^{2x}\dfrac{131}{131}\Leftrightarrow7^x=5^{2x}\Leftrightarrow7^x=25^x\Leftrightarrow x=0\)

0

x=0

`P(x)=2x^5+2x+8-3x^2-2x^5+2x^3-4x^4 `

`= (2x^5 -2x^5) -4x^4 +2x^3 -3x^2 +2x +8`

`= -4x^4 +2x^3 -3x^2 +2x +8`

Bậc của `P(x)=10`