Question

a/c + a-c/a -a^2-c^2/ac

Answer 1

$frac{a}{c}+ frac{a-c}{a}- frac{a^2-c^2}{ac}= frac{a^2+c(a-c)-(a^2-c^2)}{ac}= frac{a^2+ac-c^2-a^2+c^2}{ac}= frac{ac}{ac}=1$