Answer:25
Step-by-step explanation: first you do 5+12 which gets you 17. Then you add 17+8 and you get 25. 25 -8=17 17-12=5
 
        
             
        
        
        
Answer:
6(less than or equal sign) n+15 
Step-by-step explanation:
the less than or equal sign is a less than sign with one line under it 
 
        
             
        
        
        
Answer:
I think the first one is correct
 
        
                    
             
        
        
        
Answer:
C. (3x2 - 10) (x - 2)
Step-by-step explanation:
3x^2 - 16x +20 
Step 1: Sum = - 16x
 Product = 60x^2
Step 2: Find 2 numbers that their sum is -16 and their product is 60. If you do that correctly, then you will get two numbers: 10 and -6
Step 3: Replace -16x with the two numbers found in step 2, then you will have; 3x^2 - 6x - 10x + 20
Step 4: Factorise the equation in step 3, like so;
(3x^2 - 6x)(- 10x + 20)
3x(x - 2) -10(x - 2)
(3x - 10)(x - 2)
To check if the answer is correct, expand the bracket: (3x - 10)(x - 2)
If the bracket is opened properly, you will get 3x^2 - 16x + 20