It would be -4x+(-12)=12 good luck
        
                    
             
        
        
        
Answer:
W1 = W2 = 50k Joules (assuming W1 and W2 have the same force constant, k)
W1 - W2 = 0
Step-by-step explanation:
Work done in stretching a spring is given by 1/2ke^2
Where, k is force constant and e is extension
e1 = 30cm - 20cm = 10cm
W1 = 1/2k(e1)^2 = 1/2×k×10^2 = 50k Joules
e2 = 40cm - 30cm = 10cm
W2 = 1/2k(e2)^2 = 1/2×k×10^2 = 50k Joules
W1 = W2 = 50k Joules provided W1 and W2 have equal force constant
Therefore, W1 - W2 = 0
 
        
             
        
        
        
The main idea here is to "translate" the words into maths. 
First we need to identify the unknowns and label these. 
We need to know the number if dimes and the number of quarters. So lets say 
x: number of dimes
y: number of quarters
Now lets write equations from the written problem. 
We know that there are 36 coind total, thus: 
x + y = 36
We also know that the coins total 5.85 dollars, but it is better to count in cents, that is 585 cents. 
x are the number of dimes, their value is x*10
y are quarters with value of y*25
thus: 
10x+25y=585
We have two equations and two unknowns now, that needs to be solved to get the answer. 
x + y = 36
10x+25y=585
        
                    
             
        
        
        
| -6 | + |8| = 6 + 8 = 14 spaces...so thats gym to school
        
             
        
        
        
<span>1/5
       
This is a matter of elimination. So let's figure out how many of each display there is.
30% of 150 = 0.30 * 150 = 45 displays about electricity.
2/5 * 150 = 0.40 * 150 = 60 displays about renewable energy
1/10 * 150 = 150/10 = 15 displays about gas.
The rest of the displays are about nuclear power. So
150 - 45 - 60 - 15 = 30 displays about nuclear power. Since we want a fraction, we get 30/150
But 30/150 isn't in it's simplest form. The largest number that will evenly divide both 30 and 150 is 30. So divide both the numerator and denominator by 30
(30/30)/(150/30) = 1/5
So 1/5 of the displays are about nuclear power.</span>