An 18% increase. I just used my handy dandy calculator.
Hello :
<span>f(x)=x²+4x-5
</span><span>The axis of symmetry for a function in the form f(x)=x^2+4x-5 is x=-2 :
</span>f(x) = (x+2)² + b
f(x) x²+4x+4+b= x² +4x-5
4+b= -5
b = -9
the vertex is : (2 , -9)
The is will be -<span>11b3</span><span> - 16b</span>2<span> + </span>4b<span> + </span><span>3</span>
I cannot suggest anything other than the set of real numbers here, but maybe someone else can provide a better answer. As long as you increase or decrease x (which is a real number) then you will get a real number, or the infinite set of real numbers.