Calculus slope of a line normal to the curve HELP PLEASE

Question

Find the slope of the line normal to the curve y = 3x²-23x + 5 at x = 5

Answer 1

From

y = 3 * x^2 - 23 * x + 5

We get the derivative as

dy/dx = 6 * x - 23

At x = 5 the slope is 7. The slope of the normal line is the negative reciprocal of the slope of the line so

Normal line slope = - 1 / 7

Answer 2

First you take the derivative of y which is 6x-23. Then you plug in 5 to x and you will get 7. The slope of a line normal is 7