Answer:
Step-by-step explanation:
Answer: a11 = 3, a12 = 7, a21 = 1, a22 = -4
<u>Explanation:</u>
3x + 7y = 20
x - 4y = 9
A = ![\left[\begin{array}{ccc}3&7&20\\1&-4&9\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D3%267%2620%5C%5C1%26-4%269%5Cend%7Barray%7D%5Cright%5D)
<u>column 1 </u> <u>column 2</u>
row 1: (a11) 3 (a12) 7
row 2: (a21) 1 (a22) -4
Sqrt of 125
10^2 +b^2= 15^2
100 +b^2=225
B^2=125
No perfect square for 125 so leave it in radical form
Answer:
39.2
Step-by-step explanation:
We need to find the solution of 7 copies of sum of 8 fifths and 4.
Now, 8 fifths = 
Sum of 8 fifths and 4 = = 
Now, 7 copies of
means that we meed to multiply
7 times
7 copies = 
7 copies = 39.2
Hence, the solution is 39.2.
The answer is 10 to the 2nd power