Rotate 90 counter clockwise around the origin and then reflect over the c-axis

An equation of the line tangent to y=x^3+3x^2+2 at its point of inflection is

The square root of 9x plus 7 plus the square rot of 2x equall to 7

The mean of 10 values is 19. if further 5 values areincluded the mean becomes 20. what is the meanthese five additional values? a) 10b) 15c) 11d) 22