the product of a and b is equal to 10 more than twice the sum of a and b . if b = 9 , what is the value of b - a ?
"ab = 10 + 2 ( a + b ) 9 a = 10 + 2 a + 18 7 a = 28 a = 4 b - a = 9 - 4 = 5 b is the answer"
subtract(9, divide(add(multiply(9, const_2), 10), subtract(9, const_2)))