Question 433290
{{{5x^2=15}}} First, divide both sides by 5.
{{{x^2=3}}} Then take the sqrt of both sides.
{{{x=sqrt(3)}}}and{{{x=-sqrt(3)}}} Don't forget every time you take a square root in a quadratic equation you always get plus and minus the answer.
The x-intercepts:to find an x-intercept you always substitute 0 in for y in the function.
{{{0=5x^2-15}}} As you'll see, you get the same answer as you just got above.
The point is that solving an equation is the same as finding the function's x-intercepts.