Which relation does not represent a function

Heather is writing a quadratic function that represents a parabola that touches but does not cross the x-axis at x = -6. which function could heather be writing? fx) = x2 + 36x + 12 = x2 - 36x - 12 f(x) = -x + 12x + 36 f(x) = -x? - 12x - 36

Solve each quadratic equation by factoring and using the zero product property. 14x - 49 = x^2

What is always true when two whole numbers are subtracted?