Answer:
9
Step-by-step explanation:
f(3) = 2(3) + 3
= 9
Answer:
Base area of box = 
Step-by-step explanation:


Base area of a rectangular box is a rectangle
Area of a rectangle (base area)= length times width


Base area = 
Multiply x inside the parenthesis
Base area of box = 
2x+3=7
2x+3-3=7-3
Whenever moving a number to the other side you have to change the sign .
2x= 4
x=2