line passing through (0,3) that is perpendicular to x + y = 5

I thought it was y = -2x + 3

Answer is: y = x + 3
How did they get this?

Thank you so much

You should know that perpendicular lines have slopes that are negative reciprocals of each other.

It is easy to see that the slope of the given
x+y=5 is -1
Thus the slope of the new line is +1
that is, it must be y = x + b, where b is the y-intercept.
And isn't (0,3) the y-intercept

so clearly y = x+3 is the new line