Giai he phuong trinh
x√y + y√x=30
x√x + y√y =35
Moi nguoi giai ho minh voi
giai he phuong trinh sau voi x , y la nghiem
(5m+1)x+(3m+2)y=15
(13m-14)x-(2m-5)y=9
tim gia tri cua m sao cho x+y=3
cho x,y la so thuc thoa man x3 - y3 = -3xy(y - x)
tinh bieu thuc A= (2x - y)(y - 2x )(x - y)2
moi nguoi giai giup minh voi +_+ huhu
Có: \(x^3-y^3=-3xy\left(y-x\right)\)
\(\Leftrightarrow x^3-y^3=-3xy^2+3x^2y\)
\(\Leftrightarrow x^3-3x^2y+3xy^2-y^3=0\)
\(\Leftrightarrow\left(x-y\right)^3=0\)
\(\Leftrightarrow x-y=0\Leftrightarrow x=y\)
Khi đó bt A trở thành:
\(A=\left(2x-y\right)\left(y-2x\right)\left(y-y\right)^2=\left(2x-y\right)\left(y-2x\right)\cdot0=0\)
giup minh voi cac ban oi !!!!!!!!!!!!!!!!1
/x+y/ +/y-2/=2
/x-1/+y =3
giai he phuong trinh
B1:biến đổi (2) hoặc (1)
B2:Thay vào nhau thôi. Kết quả là
\(\hept{\begin{cases}x=-\frac{4}{3}\\y=\frac{2}{3}\end{cases}}\) hoặc \(\hept{\begin{cases}x=0\\y=2\end{cases}}\)
( x - 3) ( y +2) = -5
giai ho minh voi
giai he phuong trinh
x+y+z=2016
(x*y/x*x+x*y+y*y)+(y*z/y*y+y*z+z*z)+(z*x/z*z+z*x+x*x)=1
giai he phuong trinh x/x-1 + 2y/y+2 = 3 va 2x/x-1 - y/y+2 = -4
giai he phuong trinh
x+2\x+1\y=4
1\x^2+1\xy+x\y=3
giai he phuong trinh
2(x+y) + √(x+1) = 4
(x+y) - 3√(x+1)=-5
\(-\int^{2\left(x+y\right)+\sqrt{x+1}=4}_{2\left(x+y\right)-6\sqrt{x+1}=-10}\Leftrightarrow\int^{7\sqrt{x+1}=14}_{x+y-3\sqrt{x+1}=-5}\Leftrightarrow\int^{\sqrt{x+1}=2}_{x+y-6=-5}\Leftrightarrow\int^{x=3}_{y=-2}\) => vậy..
giai he phuong trinh
x-y=3
x3-y3=9
\(x^3-y^3=9< =>\left(x-y\right)^3+3xy\left(x-y\right)=9< =>3^3+3.xy.3=9< =>\)xy=-2
x-y =3 <=> x= y+ 3 => y(y+3) = -2 <=> y2 +3y +2 =0 <=> y= -1; x= y+3 = 2 hoặc y = -2; x= 1
vậy hệ có 2 nghiệm (x;y) = (2; -1); (1; -2)