remember understand

Question

I have such a problem, I cannot understand this task.

2.1x + 4.5y = 13.5
3.7x - 0.1y = -0.3

Answer 1

As i remember you need to find x or y first and then replace its value on one equation to find the other missing one.
i think this can be the answer
2.1x + 4.5y = 13.5
+
(3.7x - 0.1y = -0.3) *45

168.6x +0y = 0 => x = 0
0 + 4.5y = 13.5
y = 13.5/4.5 => y =3

{x:0,y:3} i think

Answer 2

Med Amine Fh thanks helped