30-f+8f=30
30+7f=30
Move +30 to the right side. Sign changes from +30 to -30.
30-30+7f=30-30
7f=0
Divde by 7
7f/7=0/7
Cross out 7 and 7, divide by 7. Becomes 1*1*f=f
f=0
Answer: f=0
 
        
                    
             
        
        
        
Answer:
11
Step-by-step explanation:
Let the no. of helmet be x
cost of 1 helmet = $12.00
cost of x helmet = $12.00*x = $12x
Let the no. of tire pumps be y
cost of 1 tire pumps = $8.00
cost of x tire pumps = $8.00*y = $8y
Given that total no. of helmet and pump is 18
thus
x + y = 18
y = 18-x
also given
total money spent is $188
thus
12x+8y = 188
using y = 18 - x
we have
12x + 8(18-x) = 188
=> 12x+ 144 - 8x = 188
=> 4x = 188-144 = 44
=> x = 44/4 = 11
Thus, no of helmet bought by Margo is 11.
 
        
             
        
        
        
They are all pretty easy all you do is multiply the cost by the amount of things you buy. For example number 4 your variables are cost (c) and songs (s). Your equation is c•s so $0.99 • s. 50 songs would be .99 • 50 which is $49.50
        
             
        
        
        
Answer:
1m
Step-by-step explanation:
hope that helps
 
        
                    
             
        
        
        
The <em>proposed</em> design of the atrium (<em>V < V'</em>) is possible since its volume is less than the <em>maximum possible</em> atrium.
<h3>Can this atrium be built in the rectangular plot of land?</h3>
The atrium with the <em>maximum allowable</em> radius (<em>R</em>), in feet, is represented in the image attached. The <em>real</em> atrium is possible if and only if the <em>real</em> radius (<em>r</em>) is less than the maximum allowable radius and therefore, the <em>real</em> volume (<em>V</em>), in cubic feet, must be less than than <em>maximum possible</em> volume (<em>V'</em>), in cubic feet.
First, we calculate the volume occupied by the maximum allowable radius:
<em>V' =</em> (8 · π / 3) · (45 ft)³
<em>V' ≈</em> 763407.015 ft³
The <em>proposed</em> design of the atrium (<em>V < V'</em>) is possible since its volume is less than the <em>maximum possible</em> atrium. 
To learn more on volumes, we kindly invite to check this verified question: brainly.com/question/13338592