HELPPPPPP PLEASEEEEEEEE Are 4x and 15 + x equivalent expressions? Explain why or why not.

Question

I just need the explanation thank you :D

Answer 1

These are not equivalent expressions. If they were equivalent they should have the same value for all x. Consider when x=0. 4⋅0 = 0 and 15 + 0 = 15.

In math when things are true, they need to be true in all cases. If there is case where a statement is false, it is a false statement. It doesn't work the same way for true statements. If a statement is true in some case, we do not know if it is always true.