What is the y-intercept of y=9x^6+1x^5+5x^4+2x^3

Whats the name of the vertical axis

Astudent draws two parabolas on graph paper. both parabolas cross the x-axis at (–4, 0) and (6, 0). the y-intercept of the first parabola is (0, –12). the y-intercept of the second parabola is (0, –24). what is the positive difference between the a values for the two functions that describe the parabolas? write your answer as a decimal rounded to the nearest tenth

Write as a product of two polynomials. 2(3–b)+5(b–3)^2