B=−13+|2,34−3x|B=-13+|2,34-3x|
Ta có: |2,34−3x|≥0|2,34-3x|≥0 với ∀x∀x
⇒−13+|2,34−3x|≥−13⇒-13+|2,34-3x|≥-13 với ∀x∀x
⇒B≥−13⇒B≥-13 với ∀x∀x
Dấu "==" xảy ra khi:
⇔|2,34−3x|=0⇔|2,34-3x|=0
⇔2,34−3x=0⇔2,34-3x=0
⇔3x=2,34⇔3x=2,34
⇔3x=11750⇔3x=11750
⇔x=11750:3⇔x=11750:3
⇔x=11750.13⇔x=11750.13
⇔x=3950⇔x=3950
Vậy AA đạt GTNGTNNN là −13-13 khi x=3950
\(B=-13+|2,34-3x|\)
\(-13+|2,34-3x|\ge-13\)
\(|2,34-3x|\ge0\) dấu ''='' xảy ra khi \(|2,34-3x|=0\)
\(\Rightarrow2,34-3x=0\)
\(\Rightarrow3x=2,34\)
\(\Rightarrow x=0,78\)