A health insurance plan has a $50 enrollment fee and a copayment of $5 for each doctor visit. The function f(x)=5x+50 gives the cost of x doctor visits. What is the cost for visiting the doctor 3 times?

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