What’s the answer don’t do explaining

What is the solution to the system of the equations? x = y - 3 x + 3y = 13

Asilkworm winds its cocoon out of one long silk fiber. to make silk thread, 3 to 10 of these silk fibers are unwound from their cocoons and combined into aa single thread with a typical length of 300 yards. choose a reasonable number of silk fibers in a thread write an equation to find the total length of the silk fibersused in 300 yards of the thread

Pls will give brainliest and all p.s u can zoom in if u cant see plss