we know that
If two numbers have a sum of zero, then we say they are additive inverses.
so
z+0.8=0 -------> the sum is equal to zero
z=-0.8------> the additive inverse of z is equal to -0.8
using a graph tool
see the attached figure
<u>the answer Part a) and part b) in the attached figure</u>
 
        
                    
             
        
        
        
Answer:
6
Step-by-step explanation:
let’s start with putting the unknown to x, in this case it is the number.
5x-5=7+3x, so now we just solve this equation.
5x-3x=7+5
2x=12
x=6
 
        
             
        
        
        
Answer:
2x+5
Step-by-step explanation:
X represents the number in "2 times a number." You could insert any number into x.