Question

Which one of these equations is correctly written in Standard Form?

x + y = −3

7x + 1.5y = −3

x + 7y = −21

−7x + y = −21

Answer 1

What is this standard form? It will be f(x)=ax+b?

Answer 2

Idk

Answer 3

Sorry what´s ldk?

Answer 4

I don't know, I think it want's to know what form is almost completed the equation