Hello !
1. System of equation

2. The substitution method
We will use the substitution method.
2.1 We want to isolate y, it's already done!

2.2 We replace y in the 2nd expression :

2.3 Now we solve the equation since we only have x
2.3.1 Solve x

2.3.2 Solve y

3. Conclusion
x = 2 and y = 1
Have a good day !