Help me please I can't skip this question.

When eating out, record the total cost of your meal (before tip) and the tip that you left. determine the percent of the cost of the meal that you left as a tip.

Given the points a(-2, 1) and b(8, 6), find the coordinates of the point c on directed line segment ab, that partitions ab in the ration 2: 3.

Find the center and the radius of the circle with the equation: x^2-2x+y^2+4y+1=0?