Bài 1:
a) $|x-\dfrac{3}{4}|≥0$
$→$ Dấu "=" xảy ra khi $x-\dfrac{3}{4}=0$
$→x=\dfrac{3}{4}$
$→A_{min}=0$ khi $x=\dfrac{3}{4}$
b) $|2-x|≥0$
$→1,5+|2-x|≥1,5$
$→$ Dấu "=" xảy ra khi $2-x=0$
$→x=0$
$→B_{min}=1,5$ khi $x=2$
Bài 2
a) $|x+2|≥0$
$→-|x+2|≤0$
$→$ Dấu "=" xảy ra khi $x+2=0$
$→x=-2$
$→C_{max}=0$ khi $x=-2$
b) $|x-3|≥0$
$→1-|x-3|≤1$
$→$ Dấu "=" xảy ra khi $x-3=0$
$→x=3$
$→D_{max}=1$ khi $x=3$