amp;P(a2,a+1)amp;L1=3x−y+1=0
Origin and P lies same side w.r.t. L1
amp;⇒L1(0)⋅L1(P)amp;∴3(a2)−(a+1)+1gt;0gt;0

amp;⇒3a2−aamp;a∈(−∞,0)∪(31,∞)..... (1)gt;0
Let L2:x+2y−5=0
Origin and P lies same side w.r.t. L2
amp;⇒L2(0)⋅L2(P)amp;⇒a2+2(a+1)−5amp;⇒a2+2a−3amp;⇒(a+3)(a−1)gt;0lt;0lt;0lt;0
∴a∈(−3,1)..... (2)
Intersection of (1) and (2)
a∈(−3,0)∪(31,1)