How do I do this ? very confusing

The triangles are similar. what is the value of x? x=

Write an equation of the line that passes through 9,2 and is parallel to the line y=5/3x+9

Use mathematical induction to prove the statement is true for all positive integers n, or show why it is false. 1^2 + 4^2 + 7^2 + + (3n - 2)^2 = [n(6n^2-3n-1)/2]