What is 2/3 written as a sum of unit fractions with the denominator of nine

There is a line with slope 1/a going through the point (a, a²). find the equation of the line perpendicular to this line at this point. (don’t let this problem intimidate you! solve the problem as you would if i’d given you specific values. just use variables instead.)

3. find the radius of circle p.4. find y.

What are the possible rational zeros of [tex]f(x) = x^4+2x^3-3x^2-4x+18[/tex]