Question

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

Answer 1

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