Answer:
23
Step-by-step explanation:
If you have something that says it is the f(x) or just f(something) then that is just telling you what the x equals. In this case, x=4 so you plug that into the equation. 
This gives you f(4)=4(4)+7. From here, you will use the order of operations to solve.
f(4)=4*4+7
f(4)=16+7
f(4)=23
 
        
                    
             
        
        
        
Answer:
largest 4 digit number × largest 3 digit number
=9999 × 999
(10000-1)×(1000-1) = (a-b)(c-b)= ac-ab-bc+b^2
10000000-10000-1000+1 = 9989001
 
        
             
        
        
        
Answer:
y=3x+1
Step-by-step explanation:
 
        
                    
             
        
        
        
Answer:
<h2>2.2</h2>
Step-by-step explanation:
Use the cosine law (look at the picture).
We have:


 → look at the second picture
 → look at the second picture
