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Answer:10 gallons of 30% solution and 30 gallons of 70% solution should be mixed.
Step-by-step explanation:
Let x represent the number of gallons of the 30% solution that should be mixed.
Let y represent the number of gallons of the 70% solution that should be mixed.
The total number of gallons of the mixture to be made is 40. This means that
x + y = 40
The 30% solution of fertilizer is to be mixed with a 70% solution of fertilizer in order to get 40 gallons of a 60% solution. This means that
0.3x + 0.7y = 0.6 × 40
0.3x + 0.7y = 24- - - - - - - - - - - - - -1
Substituting x = 40 - y into equation 1, it becomes
0.3(40 - y) + 0.7y = 24
12 - 0.3y + 0.7y = 24
- 0.3y + 0.7y = 24 - 12
0.4y = 12
y = 12/0.4
y = 30
x = 40 - y = 40 - 30
x = 10
The general formula for a equation of the form:

is:
![x=\frac{-b\pm\sqrt[]{b^2-4ac}}{2a}](https://tex.z-dn.net/?f=x%3D%5Cfrac%7B-b%5Cpm%5Csqrt%5B%5D%7Bb%5E2-4ac%7D%7D%7B2a%7D)
In this case we notice that a=1, b=-4 and c=3. Plugging this values in the general formula we get:
![\begin{gathered} x=\frac{-(-4)\pm\sqrt[]{(-4)^2-4(1)(3)}}{2(1)} \\ =\frac{4\pm\sqrt[]{16-12}}{2} \\ =\frac{4\pm\sqrt[]{4}}{2} \\ =\frac{4\pm2}{2} \end{gathered}](https://tex.z-dn.net/?f=%5Cbegin%7Bgathered%7D%20x%3D%5Cfrac%7B-%28-4%29%5Cpm%5Csqrt%5B%5D%7B%28-4%29%5E2-4%281%29%283%29%7D%7D%7B2%281%29%7D%20%5C%5C%20%3D%5Cfrac%7B4%5Cpm%5Csqrt%5B%5D%7B16-12%7D%7D%7B2%7D%20%5C%5C%20%3D%5Cfrac%7B4%5Cpm%5Csqrt%5B%5D%7B4%7D%7D%7B2%7D%20%5C%5C%20%3D%5Cfrac%7B4%5Cpm2%7D%7B2%7D%20%5Cend%7Bgathered%7D)
then:

and

Therefore, x=3 or x=1.
Answer:
If we are working in a coordinate plane where the endpoints has the coordinates (x1,y1) and (x2,y2) then the midpoint coordinates is found by using the following formula:
midpoint=(x1+x22,y1+y22)
Step-by-step explanation: