mohon bantuannya masih belum paham

f(x) = (3x+2)/(5x-7) dengan x =/= 7/5

f^2 = (f○f)(x)
f^2 = f(f(x))
f^2 = f((3x+2)/(5x-7))
f^2 = [3(3x+2)/(5x-7) + 2]/[5(3x+2)/(5x-7) - 7]
f^2 = [(9x+6+10x-14)/(5x-7)]/[(15x+10-35x+49)/(5x-7)]
f^2 = [(19x-8)/(5x-7)]/[(-20x+59)/(5x-7)
f^2 = [(19x-8)/(5x-7)] × [(5x-7)/(-20x+59)]
f^2 = (19x-8)/(-20x+59)