Can anyone please answer this perpendicular lines question?​

How do you use the elimination method for this question? explain, because i really want to understand!

(05.08a)triangle abc is transformed to similar triangle a′b′c′ below: a coordinate plane is shown. triangle abc has vertices a at 2 comma 6, b at 2 comma 4, and c at 4 comma 4. triangle a prime b prime c prime has vertices a prime at 1 comma 3, b prime at 1 comma 2, and c prime at 2 comma 2. what is the scale factor of dilation? 1 over 2 1 over 3 1 over 4 1 over 5

There are 45 questions on your math exam. you answered 810 of them correctly. how many questions did you answer correctly?