if x is a number such that x ^ 2 + 4 x - 5 = 0 and x ^ 2 - 5 x + 4 = 0 , then x =
"x ^ 2 + 4 x - 5 = ( x + 5 ) ( x - 1 ) = 0 then x = - 5 or x = 1 . x ^ 2 - 5 x + 4 = ( x - 4 ) ( x - 1 ) = 0 then x = 4 or x = 1 . thus x = 1 . the answer is c ."
divide(add(4, 5), add(2, 5))