a: \(\left|3x-4\right|+\left|3y+5\right|=0\)
=>\(\left\{{}\begin{matrix}3x-4=0\\3y+5=0\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}3x=4\\3y=-5\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}x=\dfrac{4}{3}\\y=-\dfrac{5}{3}\end{matrix}\right.\)
b: \(\left(x-2\right)^2>=0\forall x;\left(y-3\right)^2>=0\forall y\)
Do đó: \(\left(x-2\right)^2+\left(y-3\right)^2>=0\forall x,y\)
Dấu '=' xảy ra khi \(\left\{{}\begin{matrix}x-2=0\\y-3=0\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}x=2\\y=3\end{matrix}\right.\)
c: \(\left|x-1,5\right|+\left|2,5-x\right|=0\)
=>\(\left\{{}\begin{matrix}x-1,5=0\\2,5-x=0\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}x=1,5\\x=2,5\end{matrix}\right.\Leftrightarrow x\in\varnothing\)
d: |x-1,5|+|2,5-x|=1
mà \(\left|x-1,5\right|+\left|2,5-x\right|>=\left|x-1,5+2,5-x\right|=1\)
nên dấu '=' xảy ra khi (x-1,5)(2,5-x)>=0
=>1,5<=x<=2,5
