Get the app called connects! It’s really good help for math!

Just follow step by step. Follow PEMDAS (Parentheses, Exponents. Multiply/Divide, Add/Subtract)
If that little dot after the '1' is a comma, then you're correct. Melting doesn't change the mass.
Answer:
(-5,2) (-7,0)
Step-by-step explanation:
F(4)=4(4)+5
Which equals
F(4)=21