Tìm x,y
13x2+4y2-36x+12xy+25=0
Bài 1: Viết biểu thức sau dưới dạng tổng hoặc hiệu 2 bình phương
a) 9x2 + 25 - 12xy + 5y2 - 10y
b) 13x2 + 4x + 12xy + 4y2 + 1
c) x2 + 20 + 9y2 + 8x - 12
tìm x;y
a) 4x2+13y+12xy−18y−4x+104x2+13y+12xy−18y−4x+10
b) 4x2+12xy+9y2+4y2−18y−4x+104x2+12xy+9y2+4y2−18y−4x+10
c) (2x+3y)2−2(2x+3y)+1+4y2−12y+9(2x+3y)2−2(2x+3y)+1+4y2−12y+9
d) (2x+3y−1)+(2y−3)2=0
Cho x; y > 0 và x2 + 4y2 = 12xy . Khẳng định nào sau đây là khẳng định đúng?
A. log2 x + 2 y 4 =log2x-log2y
B. log2(x+2y)=2+ 1 2 (log2x+log2y)
C. log2(x + 2y) = log2x+log2y+1
D. 4log2( x + 2y) = log2x + log2y.
Chọn B.
Vì x2 + 4y2 = 12xy nên (x + 2y)2 = 16xy hay log2( x + 2y) 2= log216xy
Do đó: 2log2(x + 2y) = 4 + log2x + log2y
Vậy
Cho x ; y > 0 v à x 2 + 4 y 2 = 12 x y . Khẳng định nào sau đây là khẳng định đúng ?
A. log 2 x + 2 y 4 = log 2 x - log 2 y
B. log 2 x + 2 y = 2 + 1 2 log 2 x + log 2 y
C. log 2 x + 2 y = log 2 x + log 2 y + 1
D. 4 log 2 x + 2 y = log 2 x + log 2 y
a/ x3y2 - xy2 b/ 2x3y2 + 4x2y2 + 2xy2
c/ 3x3y - 12x2y + 12xy d/ 6x3y + 12x2y2 + 6xy3
e/ x2(x – y) + y2(y – x) f/ 9x2(x – 2 ) – 4y2(x - 2)
Giúp mình với đang cần gấp
\(a,x^3y^2-xy^2=xy^2\left(x^2-1\right)=xy^2\left(x-1\right)\left(x+1\right)\\ b,2x^3y^2+4x^2y^2+2xy^2=2xy^2\left(x^2+2x+1\right)=2xy^2\left(x+1\right)^2\\ c,3x^3y-12x^2y+12xy=2xy\left(x^2-4x+4\right)=2xy\left(x-2\right)^2\\ d,6x^3y+12x^2y^2+6xy^3=6xy\left(x^2+2xy+y^2\right)=6xy\left(x+y\right)^2\\ e,x^2\left(x-y\right)+y^2\left(y-x\right)=\left(x^2-y^2\right)\left(x-y\right)=\left(x-y\right)^2\left(x+y\right)\\ f,9x^2\left(x-2\right)-4y^2\left(x-2\right)=\left(9x^2-4y^2\right)\left(x-2\right)=\left(3x-2y\right)\left(3x+2y\right)\left(x-2\right)\)
Tick plz
a: \(x^3y^2-xy^2=xy^2\left(x^2-1\right)=xy^2\left(x-1\right)\left(x+1\right)\)
b: \(2x^3y^2+4x^2y^2+2xy^2=2xy^2\left(x^2+2x+1\right)=2xy^2\cdot\left(x+1\right)^2\)
c: \(3x^3y-12x^2y+12xy=3xy\left(x^2-4x+4\right)=3xy\cdot\left(x-2\right)^2\)
d: \(6x^3y+12x^2y^2+6xy^3=6xy\left(x^2+2xy+y^2\right)=6xy\cdot\left(x+y\right)^2\)
e: \(x^2\left(x-y\right)+y^2\left(y-x\right)=\left(x-y\right)^2\cdot\left(x+y\right)\)
f: \(9x^2\left(x-2\right)-4y^2\left(x-2\right)=\left(x-2\right)\left(3x-2y\right)\left(3x+2y\right)\)
A, 6x^2 - 12xy + 6y^2
B, 36x^2 - y^2 +10x + 25
C, 101a^2 -50a + 625
D,20x^4 - 20x^3 y^3 + 5x^2 y^4
Tìm x,y
13x^2 +9y^2 -30x +12xy +25
13x2 + 9y2 - 30x + 12xy + 25 = 0
<=> (9y2 + 12xy + 4y2) + (9x2 - 30x + 25) = 0
<=> (3y + 2x)2 + (3x - 5)2 = 0
Dễ thấy \(\left(3y+2x\right)^2\ge0;\left(3x-5\right)^2\ge0\forall x,y\)
nên \(\left(3y+2x\right)^2+\left(3x-5\right)^2\ge0\)
Dấu "=" xảy ra khi \(\left\{{}\begin{matrix}3y+2x=0\\3x-5=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}y=-\dfrac{10}{9}\\x=\dfrac{5}{3}\end{matrix}\right.\)
10x^2-12xy+5y^2+11y-36x+38=0 tim nghiem nguyen mong cac bn giup nhanh
Ta có:\(10x^2-12xy+5y^2+11y-36x+38\)
=\(9x^2-12xy+4y^2+x^2-36x+324+y^2+2.\frac{11}{2}y+\frac{11^2}{4}-\frac{1265}{4}\)
=\(\left(3x-2y\right)^2+\left(x-18\right)^2+\left(y+\frac{11}{2}\right)^2-\frac{1265}{4}\)
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