A) 25
B) 9
C) -15
D) -9
Correct Answer: C
Solution :
[c] \[({{a}^{2}}-2a-15){{e}^{ax}}+({{b}^{2}}-2b-15){{e}^{bx}}=0\] \[or({{a}^{2}}-2a-15)=0\,\,and\,{{b}^{2}}-2b-15=0\] \[or(a-5)(a+3)=0\,\,and\,\,(b-5)(b+3)=0\] i.e., \[a=5\] or \[-3\] and \[b=5\] or \[-3\] \[\therefore a\ne b\]. Hence, \[a=5\] and \[b=-3\] or \[a=-3\] and \[b=5\] or \[ab=-15\].You need to login to perform this action.
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