# The sum of the two numbers is 12. If one number is doubled and the other is left unchanged

**The sum of the two numbers is 12. If one number is doubled and the other is left unchanged, then these numbers add up to 16. Find the original numbers.**

Let the first number be x and the second y. By the condition of the problem, it is known that the sum of these two numbers is (x + y) or 12. If the first number is doubled, then it becomes equal to 2x, and the second number is left unchanged, then the sum of these numbers becomes (2x + y ) or 16. Let’s compose a system of equations and solve it.

{x + y = 12; 2x + y = 16.

From the first equation of the system, we express y through x.

y = 12 – x.

Let us substitute expression (12 – x) in the second equation instead of y.

2x + 12 – x = 16;

x = 16 – 12;

x = 4 – the first number;

y = 12 – x = 12 – 4 = 8.

Answer. (4; 8).