Question

What is the solution of the system?

{2x+y=15
{x−y=3

The lesson is Linear Combination with Multiplication if that helps.

Answer 1

2x + y = 15
x - y = 3
---------------add
3x = 18
x = 18/3
x = 6

x - y = 3
6 - y = 3
-y = 3 - 6
-y = -3
y = 3

solution is (6,3)