We can start by eliminating y. Seeing as they already have opposite coefficients, no multiplication or division needs to be done. So, add the two equations together. 3.2x + (-1.6x) = 1.6x. 4.2 + 3.4 = 7.6. 0.5y + (-0.5y) = 0. This leaves us with 1.6x = 7.6. Now divide both sides by 1.6 to get x = 4.75.
Now we can eliminate x. Since the coefficients of x are not opposites, we need to multiply the bottom equation by 2 on both sides. That leaves us with -3.2x - y = 6.8. Now we can add both equations together. 3.2x + (-3.2x) = 0. 0.5y + (-y) = -0.5y. 4.2 + 6.8 = 11. This leaves us with -0.5y = 11. Divide both sides by -0.5 to get y = -22.
