Please help will give brainliest answer

See image below

Step-by-step explanation:

When reflected across the y axis, The point coordinates are transformed the following way:

A = (2, 2) goes to A' = (-2, 2)

B = (2, 4)  goes to B' = (-2, 4)

C = (5 3)  goes to (-5, 3)

And the drawing of the new triangle is shown in red in the attached image

In basicallity if a question such as this pops up, the correct way to go would first be to graph this. y=x-4 would be equivalent to x=4.

My paper work is below:

y = x - 4

0 = x - 4

-x = -4

x = 4

Hope this helped..