Please help me and put the answer down for me so i understand it (grade 8)

Determine the number of girls in a math class with 87 boys if there are 25 girls for every 75 boys

Isabel graphed the following system of equations. 2x – y = 6 y = -3x + 4 she came up with the solution (2,-2). what were the 3 steps she did to get that solution? (make sure they are in the correct order)

Ab and bc are tangent to circle d. find x is ab = 3x + 8 and bc = 26. find x