Question

solve
the function y = x2 − 18x.

Answer 1

Solve the function means: find the roots of the curve..where it touches/crosses the x-axis


y = x2 − 18x

this quadratic function could be solved by factoring or by the quadratic formula in general

Let's try factoring....

$y=x^2-18x\\~\\y=x(x-18)$

so x=0  OR x-18=0
therefore:
x=0 or x=18

Hence 0 and 18 are the solutions for this function...

and you can say that the points (0,0) and (18,0) are the roots of this quadratic.


I hope that helps!  

Answer 2

Well, technically, there are infinitely many solutions as there is no restriction upon the domain, values of x for the function.

If you MEANT to find the value of x when y=0 then:

x^2-18x=0  factor

x(x-18)=0

So there are two solutions, when x=0 or 18