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
= 
Answer:
Sheila earned $120 in interest.
Step-by-step explanation:
In order to calculate the interest earned by Sheila we can use the simple interest formula shown bellow:
i = P*r*t
Where i is the interested earned, P is the amount invested, r is the interest rate and t is the total time. For this case we have:
i = 800*0.03*5
i = 24*5
i = 120
Sheila earned $120 in interest.
Answer:
I was not sure to what decimal point to round it to
a) Fraction: 2/7 Decimal: 0.28571 Percent: 28.571 %
b) Fraction: 5/7 Decimal: 0.71428 Percent: 71.428 %
c) Fraction: 1/7 Decimal: 0.14285 Percent: 14.285 %
Whats the question tell me and i'll try to help
