the average age of a , b and c is 25 years . if the average age of a and c is 29 years , what is the age of b in years ?
"age of b = age of ( a + b + c ) â € “ age of ( a + c ) = 25 ã — 3 â € “ 29 ã — 2 = 75 â € “ 58 = 17 years a"
subtract(multiply(25, const_3), multiply(29, const_2))