Find the axis of symmetry for this parabola y=-5x^2-10x-15 write it as an equation

Axis of symmetry is the x value of the vertex

the x value of the vertex, in form
y=ax^2+bx+c is -b/(2a)

so
y=-5x^2-10x-15
a=-5
b=-10

x value of vertex is -(-10)/(2*-5)=10/-10=-1
x=-1 is axis of symmetry

X= -1
Is this what you were looking for? 

You would plot 83 on the 83 line and you would plot -113 on the -113 line.

This is a robot. try again lol. maybe you attached the wrong image.