Answer:
Step-by-step explanation:
Given that a solution containing 12% alcohol is to be mixed with a solution containing 4% alcohol to make 20 gallons of solution containing 9% alcohol.
Let x gallons of 12% alcohol be mixed with y gallons of 4% alcohol.
Total gallons
Alcohol content in the total mixture 

b) Two equations are

c) This is of the form Ax = B
where A =![\left[\begin{array}{ccc}1&1\\12&4\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%261%5C%5C12%264%5Cend%7Barray%7D%5Cright%5D)
Inverse is ![\frac{1}{4-12} \left[\begin{array}{ccc}4&-1\\-12&12\end{array}\right]\\=\frac{-1}{8} \left[\begin{array}{ccc}4&-1\\-12&12\end{array}\right]\\](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B4-12%7D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D4%26-1%5C%5C-12%2612%5Cend%7Barray%7D%5Cright%5D%5C%5C%3D%5Cfrac%7B-1%7D%7B8%7D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D4%26-1%5C%5C-12%2612%5Cend%7Barray%7D%5Cright%5D%5C%5C)
Solution set is A inverse *B
= 
Step-by-step explanation:
-3x-9
divide the equation by -1 so that the -1's are taken from -3x and -9. so the -1 goes on the outside of 3x+9
-1(3x+9)
then divide the equation by 3 since 3x and 9 is divisible by 3.
(-1)(3)(3/3x+9/3)
-3(x+3)
Now we can expand again to check the problem
-3 times x=-3x
-3 times 3=-9
and add
-3x-9
Hope that helps :)
Answer:
3600 miles on 240 gal
Step-by-step explanation:
80 gal can go 1200
160 gal can go 2400
240 gal can go 3600