Solve the system of linear equations y+2.3=0.45x -2y=4.2-7.8

Solve the following system using substitution:
{y + 2.3 = 0.45 x
{-2 y = -3.6

In the second equation, look to solve for y:
{y + 2.3 = 0.45 x
{-2 y = -3.6

-3.6 = -18/5:
-2 y = -18/5

Divide both sides by -2:
{y + 2.3 = 0.45 x
{y = 9/5

Substitute y = 9/5 into the first equation:
{4.1 = 0.45 x
{y = 9/5

In the first equation, look to solve for x:
{4.1 = 0.45 x
{y = 9/5

4.1 = 41/10 and 0.45 x = (9 x)/20:
41/10 = (9 x)/20

41/10 = (9 x)/20 is equivalent to (9 x)/20 = 41/10:
{(9 x)/20 = 41/10
{y = 9/5
Multiply both sides by 20/9:
  {x = 82/9
                {y = 9/5