if x / y = 7 / 3 , then ( x + y ) / ( x - y ) = ?
"any x and y satisfying x / y = 7 / 3 should give the same value for ( x + y ) / ( x - y ) . say x = 7 and y = 3 , then ( x + y ) / ( x - y ) = ( 7 + 3 ) / ( 7 - 3 ) = 5 / 2 . answer : b ."
divide(add(7, 3), subtract(7, 3))