She is not correct because “value of expressions” mean the result which for this it is 16-13 =3 and she is wrong. please mark me brainly! Hope this helps! :D
y ∈ R | -∞ < y < ∞ just means that the range for y is all real numbers in a function. For y to be all real numbers, the function, when graphed, has to have no top or bottom limit. The only graphs without top or bottom limits are D and E.