Question

Reflection over the line y = x of the point (-7,4)

Answer 1

In transformations, the original figure is called "Pre-Image" and the figure obtained after the transformation is called "Image".

In this case, you know that the Pre-Image is the following point given in the exercise:

$(-7,4​)$

By definition, the rule of a reflection over the line

$y=x$

is the following:

$(x,y)\rightarrow\mleft(y,x\mright)$

Therefore, applying this rule to the point given in the exercise, you get that its Image is:

$\mleft(-7,4\mright)​\rightarrow(4,-7)$

The answer is:

$(4,-7)$