If the set of all a R, for which the equation 2x2 + (a - 5)x + 15 = 3a has no real root, is the interval ( , ), and X = \x Z; < x < \, then x X x2 is equal to:
(1) 2139
No real root ⇒ D<0 for 2x2+(a-5)x+(15-3a)=0
(a-5)2-8(15-3a)<0 ⇒ a2+14a-95<0 ⇒ (a+19)(a-5)<0 ⇒ a (-19,5)
X=\-18, ,4\ ⇒ x2= 118k2+ 14k2
= 18 19 376+30=2109+30
∴ =2139
Answer: (1)
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