Answer:
Every parabola has a turning point called the axis of symmetry,so for this question you just have to find the turning points
x turning point= -b/2a,and the y turning point is gotten by replacing the value of x in the equation
y=(x+1)(x-4)
=x^2-3x-4
a is 1,b is -3 and c is -4
x= -(-3)/2(1)
=1.5
and y=x^2-3x-4
=1.5^2-3(1.5)-4
= -6.25
therefore the axis of symmetry is (1.5,-6.25)
I hope this helps