We have an equation with parentheses. To make our lives easier, first get rid of the parentheses. We do this by using the distributive property.
It is used like this: a(b + c) = ab + ac.
Use the distributive property on the left-hand side.
3(x - 1) = 6
3x - 3 = 6
Now we have an equation that is easier.
The x variable is being multiplied by 3 and added to -3.
Reverse all of these operations with their inverse operation.
3x - 3 = 6
3x = 9 <--- I got rid of the -3 term by using the inverse of subtraction. Addition.
                  And I did the same for both sides to keep the equation true.
x = 3 <--- The inverse of multiplication is division.
                So, I divided both sides by 3.
So, x is equal to 3.
        
             
        
        
        
We divide 40 by 1/2:-
40 /  1/2  = 40 * 2/1   = 80 answer
        
             
        
        
        
Answer:
x = 4y + 28
Step-by-step explanation:
x/4 - 7 = y
+7              +7
x/4 = y + 7
× 4             × 4
x = 4y + 28
 
        
                    
             
        
        
        
Answer:
There were 39 children at the party
Step-by-step explanation:
Here, we want to know the number of children at the party 
To do this, we have to add the y-values ( frequencies of the age grades)
We have this as;
8 + 8 + 7 +10 + 6 = 39 
 
        
             
        
        
        
A ∩ B = {3, 6, 9, 12} ∩ {2, 4, 6, 8, 10, 12} 
 = {6, 12}