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
= 
9514 1404 393
Answer:
(b) 38.5
Step-by-step explanation:
The polygon is a trapezoid with bases 4 and 7 and height 7. Its area is given by the formula ...
A = (1/2)(b1 +b2)h
A = (1/2)(4 +7)(7) = 77/2
A = 38.5 . . . . square units
Answer:
|2|, |11 ¾|, |-12|, |-20.5|
Step-by-step explanation:
When you have absolute value, you basically remove the negative symbol.
For CO2 there is one atom of carbon and two atoms of oxygen. For H2O, there is one atom of oxygen and two atoms of hydrogen.
The formula:
A = bh + L (s1 + s2 + s3)
A: area
b: base
h: height
L: length
s1: side 1 (cross-sectional area)
s2: side 2 (cross-sectional area)
s3: side 3 (cross-sectional area)
Here’s an example (see attached image)
A = (4 x 6) + (12 x [7 + 7 + 4])
A = (24) + (12 x 18)
A = 24 + 216
A = 240cm^2
I hope this helped? Comment if you need more explanation or anything!
