The sum of pete's and sam's ages is 30. five years ago, pete was 3 times as old as sam. how old is sam?

let p = pete's age, s = sam's age, and p + s = 30. which of the following equations would complete the system?

p - 5 = 3s
p - 5 = 3s - 5
p - 5 = 3s - 15

Answer : The equation complete the system is, and the Sam is 10 years old.

Step-by-step explanation :

As we are given that sum of Pete's and Sam's ages is 30. Thus, the equation will be:

    ..............(1)

       ..............(A)

And, five years ago, Pete was 3 times as old as Sam. Thus, the equation will be:

    ..............(2)

Now substituting equation A in equation 2, we get:

Now put the value of 'S' in equation A, we get the value of 'P'.

The age of Pete is, 20 and the age of Sam is, 10

Thus, the equation complete the system is, and the Sam is 10 years old.

ab will be equal to