Answer:If Mary spent half of her allowance the equation will begin with 1/2x or 0.5x where x is her allowance and 0.5 is half of her allowance spent. Mary also earned 7 dollars by washing the car so this will be added to her allowance spent. 
The problem says that after Mary has spent half of her allowance at the movies she was left with 18 dollars so that means that the equation must be equal to 18.
 
The equation you want to set up is
0.5x+7=18
Where, 18-7=11
0.5x=11
11/.5 = x
x = $22
 
Thus, Mary has a weekly allowance of 22 dollars.
Step-by-step explanation:
 
        
                    
             
        
        
        
we know that
when you want to figure out a tip, you take your total bill and multiply it by the percentage you would like to tip them
so
15%=15/100------> 0.15
$63*0.15=$9.45
the answer is
$9.45
 
        
             
        
        
        
Answer:
that is false! im pretty sure!
let me know if u need any more help cutie!
Step-by-step explanation:
 
        
             
        
        
        
Answer:
w = 11
Step-by-step explanation:
<u>Step 1:  Subtract 4 from both sides</u>
15 = w + 4
15 - 4 = w + 4 - 4
11 = w
Answer:  w = 11
 
        
                    
             
        
        
        
Answer:
(0,3) and (7,0) are solutions.
Step-by-step explanation:
In a pair of coordinates, they are always listed as (x,y). Since this is the case, you plug in each coordinate to their respective places. 
For (0,3)
3(0) + 7(3) = 21
0 + 21 = 21
For (7,0)
3(7) + 7(0) = 21
21 + 0 = 21
To double check that (1,2) isn't a solution:
3(1) + 7(2) = 21
3 + 14 = 21
17 = 21 X
This doesn't work.
Marking as Brainliest is much appreciated.