The correct option is B 1
√−x2+10x−16<x−2 is meaningful when
−x2+10x−16≥0
⇒x2−10x+16≤0⇒(x−2)(x−8)≤0⇒x∈[2,8] ⋯(1)
Now, √−x2+10x−16<x−2
⇒−x2+10x−16<(x−2)2⇒2x2−14x+20>0⇒x2−7x+10>0
⇒(x−2)(x−5)>0
⇒x∈(−∞,2)∪(5,∞) ⋯(2)
From (1) and (2),
x∈(5,8]
⇒a=6,b=7,c=8
∴2a+3b−4c=12+21−32=1
Hence, the value of 2a+3b−4c is 1.