Hello can someone help me understand this explanation? I don’t understand how they got 5x=5
Thank you!

Use the function nest to evaluate p(x) = 1 + x + · · · + x50 at x = 1.00001. (use the matlab ones command to save typing.) find the error of the computation by comparing with the equivalent expression q(x) = (x51 − 1)/(x − 1).

Complete the equation of the line through (−10,3) and (−8,−8). use exact numbers.

Could someone with number 1 and 2