The sum of two sides of a triangle must be greater than the third side
1) 5+9>14
14>14 It is incorrect so you can’t have these lengths
2)7+7>15
14>15 X
3)1+2>4
3>4 X
4)3+6>8
9>8
6+8>3
14>3
8+3>6
11>6
So the fourth choice is correct
Ay^2+2ay-3a
a(y^2+2y-3)
a(y-1)(y+3)