Question

The sum of 3 times one number, x, and 6 times a second number, y, is 111. If the sum of the two numbers is 27, find the two numbers.

Enter a system of equations to represent the situation, then solve the system.

Answer 1

Explanation:

using elimination method because this is a simultaneous equation

3×x+6×y=111

x+y=27

1×[3x+6y=111]

3×[x+y=27]

3x+6y=111—equation 1

3x+3y=81—equation 2

substrate equation 1 from equation 2

3y=30

divide both sides by 3

y=10

substitute 10 for y in equation 1

3x+6y=111

3x+6(10)=111

3x+60=111

3x=111-60

3x=51

divide both sides by 3

x=17