$|2x-1| = |3x-4|$
$⇒$ \(\left[ \begin{array}{l}2x-1=3x-4\\2x-1=-3x+4\end{array} \right.\)
$⇒$ \(\left[ \begin{array}{l}x=3\\x=1\end{array} \right.\)
Vậy $x$ $∈$ `{3;1}`
$B = |x+1| + 2(6,3 - 3y)^2 + 3$
Vì: $|x+1|;(6,3-3y)^2 ≥ 0 ∀ x;y$
$⇒ B = |x+1| + 2(6,3 - 3y)^2 + 3 ≥ 0 + 0 + 3 = 3$
Dấu " $=$ " khi : $\left\{\begin{matrix}x=0-1=-1& \\ y=6,3:3=2,1&\end{matrix}\right.$
Vậy $B$ đạt $GTNN=3$ khi `(x;y)=(-1;2,1)`