Please help Pythagorean theorem

please answer all the question

What is the value of x? 3x + (6x - 6) = 4(2x-2)

What is the smallest integer n such that n\sqrt{2} is greater than 20

Determine whether the points (–3,–6) and (2,–8) are in the solution set of the system of inequalities below. x ? –3 y < 5? 3x + 2 a. the point (–3,–6) is not in the solution set, and the point (2,–8) is in the solution set. b. neither of the points is in the solution set. c. the point (–3,–6) is in the solution set, and the point (2,–8) is not in the solution set. d. both points are in the solution set.