a=17 ;b=-3,5 chac chan ban nhe

a=17

b=3,5

k mih nha  mih dang am

a) Do \(\left|x\right|\ge0\)

\(\Rightarrow A=\left|x\right|+5\ge5\)

\(minA=5\Leftrightarrow x=0\)

b) Do \(\left|x-\dfrac{2}{3}\right|\ge0\)

\(\Rightarrow B=\left|x-\dfrac{2}{3}\right|-4\ge-4\)

\(minB=-4\Leftrightarrow x=\dfrac{2}{3}\)

c) Do \(\left|3x-1\right|\ge0\)

\(\Rightarrow C=\left|3x-1\right|-\dfrac{1}{2}\ge-\dfrac{1}{2}\)

\(minC=-\dfrac{1}{2}\Leftrightarrow x=\dfrac{1}{3}\)

\(A=\left|x\right|+5\ge5\)

Dấu \("="\Leftrightarrow x=0\)

\(B=\left|x-\dfrac{2}{3}\right|-4\ge-4\)

Dấu \("="\Leftrightarrow x-\dfrac{2}{3}=0\Leftrightarrow x=\dfrac{2}{3}\)

\(C=\left|3x-1\right|-\dfrac{1}{2}\ge-\dfrac{1}{2}\)

Dấu \("="\Leftrightarrow3x-1=0\Leftrightarrow x=\dfrac{1}{3}\)

\(a,A=\left|3,4-x\right|+1,7\ge1,7\)

Dấu \("="\Leftrightarrow3,4-x=0\Leftrightarrow x=3,4\)

\(c,C=\left|4x-3\right|+\left|5y+7,5\right|+17,5\ge17,5\)

Dấu \("="\Leftrightarrow\left\{{}\begin{matrix}4x-3=0\\5y+7,5=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=\dfrac{3}{4}\\y=-\dfrac{3}{2}\end{matrix}\right.\)

A=|2x+1|-3/4>=-3/4

Dấu = xảy ra khi x=-1/2

GTNN A =20

GTLN  B = 3

 hãy tìm hiểu về gttđ sẽ biết vì sao

gttd là gì vậy bạn

\(P=\left|x-\frac{20}{11}\right|+\frac{2}{3}\ge\frac{2}{3}\)( vì \(\left|x-\frac{20}{11}\right|\ge0\forall x\))

Min P = 2/3 

\(\Leftrightarrow\left|x-\frac{20}{11}\right|=0\)

\(\Leftrightarrow x=\frac{20}{11}\)

P = | x - 20/11 | + 2/3

| x - 20/11 | ≥ 0 ∀ x => | x - 20/11 | + 2/3 ≥ 2/3

Đẳng thức xảy ra <=> x - 20/11 = 0 => x = 20/11

=> MinP = 2/3 <=> x = 20/11