giai phuong trinh x^2+y^2+z^2=y(x+z)
Giai phuong trinh x2+ y22+z22=y(x+z)
giai phuong trinh xy+xz=2(x+y+z); xy+yz=3(x+y+z); xz+yz=4(x+y+z)
TH1:x,y,z=0
TH2:x=2\(\frac{3}{10}\)
y=3\(\frac{5}{6}\)
z=11\(\frac{1}{2}\)
giải ra cơ kết quả mik cx có mà hình như KQ sai rồi
à đúng rồi mà cách giải là sao v chỉ mik vs
giai phuong trinh sau :
x +y+z =2 và 2xy -z2=4
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:
a) \(\hept{\begin{cases}\left(x+y\right).\left(y+z\right)=187\\\left(y+z\right).\left(z+x\right)=154\\\left(z+x\right).\left(x+y\right)=238\end{cases}}\)
b) \(\hept{\begin{cases}x^2-y^2=1\\4x^2-5xy=2\end{cases}}\)
\(Taco:\)
\(\left(x+y\right)\left(y+z\right)=187\Leftrightarrow xy+xz+yy+yz=187\)
\(\left(y+z\right)\left(z+x\right)=154\Leftrightarrow yz+xy+zz+xz=154\)
\(\left(z+x\right)\left(x+y\right)=238\Leftrightarrow xz+zy+xx+xy=238\)
\(\Rightarrow\left(x+y\right)\left(y+z\right)+\left(x+z\right)\left(x+y\right)+\left(y+z\right)\left(z+x\right)=579\)
\(\Leftrightarrow xy+zx+yy+yz+yz+xy+zz+xz+xz+zy+xx+xy=579\)
\(\Leftrightarrow3\left(xz+xy+yz\right)+x^2+y^2+z^2=579\)
\(\left(z+x\right)\left(x+y\right)-\left(x+y\right)\left(y+z\right)=51\)
\(\Leftrightarrow\left(x+y\right)\left(x-y\right)=x^2-y^2=51\)
\(\left(z+x\right)\left(x+y\right)-\left(y+z\right)\left(x+z\right)=84\)
\(\Leftrightarrow\left(x+z\right)\left(x-z\right)=84\Leftrightarrow x^2-z^2=84\)
\(\Leftrightarrow y^2-z^2=33\)
đến đây tịt
ak tớ bt cách giải rồi cần thì ib ns tớ lm :v
Giai he phuong trinh:
a) \(\left\{{}\begin{matrix}\left(x+y\right).\left(y+z\right)=187\\\left(y+z\right).\left(z+x\right)=154\\\left(z+x\right).\left(x+y\right)=238\end{matrix}\right.\)
b) \(\left\{{}\begin{matrix}x^2+y^2+z^2=xy+yz+xz\\x^{2019}+y^{2019}+z^{2019}=3^{2020}\end{matrix}\right.\)
Giai phuong trinh:
\(x+y+z-6046=2\sqrt{x-2019}+4\sqrt{x-2020}+6\sqrt{x-2021}\)
\(x+y+z-6046=2\sqrt{x-2019}+4\sqrt{y-2020}+6\sqrt{z-2021}\)
\(\left(x-2019\right)+\left(x-2020\right)+\left(x-2021\right)+1+4+9\)\(=2\sqrt{x-2019}+4\sqrt{y-2020}+6\sqrt{z-2021}\)
đặt :\(\hept{\begin{cases}\sqrt{x-2019}=a\\\sqrt{y-2020}=b\\\sqrt{z-2021}=c\end{cases}\left(đk:a,b,c\ge0\right)}\)
PT <=> \(a^2+b^2+c^2+1+4+9=2a+4b+6c\)
\(\Leftrightarrow\left(a-1\right)^2+\left(b-2\right)^2+\left(c-6\right)^2=0\)
\(\Leftrightarrow\hept{\begin{cases}a-1=0\\b-2=0\\c-3=0\end{cases}\Leftrightarrow\hept{\begin{cases}a=1\\b=2\\c=3\end{cases}\left(tm\right)}}\)
\(\Rightarrow\hept{\begin{cases}x=2020\\y=2024\\z=2030\end{cases}}\)
tim nghiem nguyen cua cac phuong trinh:
xyz=4(x+y+z) (x+y+z)
5(x+y+z+t)+7=xyzt
nho giai cho minh nhe
trinh bay ra nhe
minh tink cho bn bn tink vho minh voi nhe
giai he phuong trinh
x+y+xy=11y+z+zy=47z+x+zx=35\(x+y+xy=11\Leftrightarrow x\left(y+1\right)+y+1=12\Leftrightarrow\left(x+1\right)\left(y+1\right)=12\)(1)
\(y\left(z+1\right)+z+1=48\Leftrightarrow\left(y+1\right)\left(z+1\right)=48\left(2\right)\)
\(z\left(x+1\right)+x+1=36\Leftrightarrow\left(z+1\right)\left(x+1\right)=36\left(3\right)\)
Lấy vế nhân vế của (1) (2) và (3) ta đc : \(\left[\left(x+1\right)\left(y+1\right)\left(z+1\right)\right]^2=12\cdot36\cdot48=144^2\)
=> \(\left(x+1\right)\left(y+1\right)\left(z+1\right)=144\) hoặc = -144
(+) Với \(\left(x+1\right)\left(y+1\right)\left(z+1\right)=144\)
=> z + 1 = 144 : 12 = 12 => z = 11
=> \(x+1=144:48=3\Rightarrow x=2\)
=> \(y+1=144:36=4\Leftrightarrow y=3\)
(+) Với ( x +1 )( y +1 )( z + 1 ) = -144 ( tương tự )