Lets call x the amount of 18% solution and y the amount of 40% solution, and write as equations the info of the problem:
18x + 40y = 10(20)
x + y = 10
lets multiply the second equation by -18 and add to the first:
 18x + 40y = 200
-18x -<span> 18y = -180
</span>----------------------
0 + 22y = 20
y = 20/22 = 10/11
and substitute in the original equation:
x <span>+ y = 10
</span>x = 10 - y
x = 10 - 10/11
x = 110/11 - 10/11
x = 100/11
so they have to use 100/11 liters of 18% solution and 10/11 liters of 40% solution
        
             
        
        
        
ANSWER
See attachment
EXPLANATION
The given equations are:
y = −2x + 13
y = 2x − 3
We equate the two equations to get
−2x + 13=2x − 3
Group similar terms:
-2x-2x=-3-13
-4x=-16
Divide both sides by -4,
x=4
Put x=4 into equation (2)
y=2(4)-3
y=5
The two graphs should intersect at:
(4,5)
 
        
                    
             
        
        
        
Answer:
y=-1/3x+15
Step-by-step explanation:
You only need to know the y-intercept which is 15, if you drew an imaginary line along the middle of the dots it would go through 15 and not 12. 
 
        
             
        
        
        
<span>Total = Principal × ( 1 + Rate )<span>^years
</span></span><span>Total = 150,000 * (1.055) ^ 30
</span>Total = 150,000 *
<span>
<span>
<span>
4.9839512884
</span></span></span>Total =
<span>
<span>
<span>
747,592.69</span></span></span>
<span>Total = 150,000 * (1.065) ^ 30
</span><span><span><span>Total = 150,000 * 6.614366163
</span>
</span>
</span>
<span>Total = 992,154.92</span>
Difference = 992,154.92 -<span>747,592.69 =
</span><span>244,562.23
</span>
Source:
http://www.1728.org/compint.htm
online interest calculator
        
             
        
        
        
Answer:
The lateral surface is 120   , which agrees with the third answer option of the list.
, which agrees with the third answer option of the list.
Step-by-step explanation:
Notice that the prism has 5 equal lateral faces, which are all rectangles of eight 6". The width of the prisms can be obtained by using the fact that the perimeter of the pentagon is 20", which gives a side length of 20/5 = 4 " which is the same as the with of the lateral rectangles.
Then the lateral area of the prism is:
Lateral area= 5 (6" x 4") = 5 (24) =  120 