the average age of a , b and c is 28 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 ) = 28 ã — 3 â € “ 29 ã — 2 = 84 â € “ 58 = 26 years b"
subtract(multiply(28, const_3), multiply(29, const_2))