Question

Like addition, subtraction, etc., we define a new operation . For example, if we write 4 5 then its value will be 4⇥2+5 = 13, if we write 5 4 then its value will be 5⇥2+4 = 14, and so on. In general, if a and b are two numbers then the value of a b can be given by a b = 2a + b. Now solve the following problem.
If a b = 18 and b a = 21, then find the value of (3a) (5b).

Answer 1

Answer:

153

Step-by-step explanation:

3×21+5×18

63+90

153