Since the lines are parallel, you know that they have the same slope, which is 2. If you look at the coordinate grid you can see that line y_{2} crosses the y-axis at (0, 1), making the y-intercept 1. Now that you know the slope is 2 and the y-intercept is 1, you can piece those into a slope-intercept equation.
y = mx + b where m is the slope and b is the y-intercept
y_{2} = 2x + 1