Question 919973
when the equation is reflected about the y-axis.
(x,y) becomes (-x,y)
you get the same y value that is the same distance from the y-axis but on opposite sides of it.


in f(x) terms, this means that f(x) is equal to f(-x)


your original equation is y = 2x + 3


replace x with (-x) an dyou get y = 2 * -x + 3 which becomes y = -2x + 3.


that's your reflected equation.


the graph of both equations will show you that the equations are symmetric about the y-axis.


this means that x = 3 becomes y = 2x + 3 which becomes y = 9 in the original equation.


this means that x = -3 becomes y = -2x + 3 which becomes y = 9 in the reflected equation.


the graphs looks like this:


a horizontal line has been placed at y = 9 so you can see that, when y = 9, x = 3 or -3.


{{{graph(600,600,-5,5,-12,12,2x+3,-2x+3,9)}}}