I need help with two questions 1: How do you slove -8 + m = 20

2: How do you slove -8x = -64

How do you solving the solution of each system using elimination?

72 the length of a side of a triangle is 36. a line parallel to that side divides the triangle into two parts of equal area. find the length of the segment determined by the points of intersection between the line and the other two sides of the triangle.

Sole the equation 6n + 9 = -3n - 21 - 6 for n