problem, but I d

Hi! I needed a solution for two different variable; the answer above shows the same two variables twice

In the right triangle ABC, CD¯¯¯¯¯CD¯ is an altitude, and c=e+f   By combining three equations, it can be shown that a2+b2=c2. One of the equations is c=e+f. Which of the following could be the other two equations?     b/c=e/b and a/c=f/a   b/c=e/b and c/a=f/a   c/b=e/b and a/c=f/a   b/a=e/b and a/b=f/a

[7×+y=13 [28×+4y=-12 Classify each system and determine the number of solutions