X+ y is rational, must x and y each be rational

The graph shown is the graph of which function?

Write a polynomial function f of least degree that has rational coefficients, a leading coefficient of 1, and the given zeros. 3, 4+2i, 1+(sqrt)7 the answer is supposed to be: f(x)=x(^5)-13x(^4)+60x(^3)-82x(^2)-144x+360 what am i doing wrong?

Simplify. (-2)^-3 a. -8 b. -1/8 c. 1/8 d. 8