Answer:
Step-by-step explanation:
Let's solve this problem step-by-step. The library had 1,500 books in 2011. The ratio of books in 2011 and in 2012 is 1:2. Therefore, let the number of books in 2012 be 
.
We have the following proportion:
Therefore, there were 3,000 books in 2012. The ratio of books in 2012 and in 2013 is 2:5. Let the number of books in 2013 be 
.
We have:
Therefore, there were 7,500 books in 2013.
Number of weekend minutes used: x
Number of weekday minutes used: y
This month Nick was billed for 643 minutes:
(1) x+y=643
The charge for these minutes was $35.44
Telephone company charges $0.04 per minute for weekend calls (x)
and $0.08 per minute for calls made on weekdays (y)
(2) 0.04x+0.08y=35.44
We have a system of 2 equations and 2 unkowns:
(1) x+y=643
(2) 0.04x+0.08y=35.44
Using the method of substitution
Isolating x from the first equation:
(1) x+y-y=643-y
(3) x=643-y
Replacing x by 643-y in the second equation
(2) 0.04x+0.08y=35.44
0.04(643-y)+0.08y=35.44
25.72-0.04y+0.08y=35.44
0.04y+25.72=35.44
Solving for y:
0.04y+25.72-25.72=35.44-25.72
0.04y=9.72
Dividing both sides of the equation by 0.04:
0.04y/0.04=9.72/0.04
y=243
Replacing y by 243 in the equation (3)
(3) x=643-y
x=643-243
x=400
Answers:
The number of weekends minutes used was 400
The number of weekdays minutes used was 243
Answer:
The determinant is 15.
Step-by-step explanation:
You need to calculate the determinant of the given matrix.
1. Subtract column 3 multiplied by 3 from column 1 (C1=C1−(3)C3):
![\left[\begin{array}{ccc}-25&-23&9\\0&3&1\\-5&5&3\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-25%26-23%269%5C%5C0%263%261%5C%5C-5%265%263%5Cend%7Barray%7D%5Cright%5D)
2. Subtract column 3 multiplied by 3 from column 2 (C2=C2−(3)C3):
![\left[\begin{array}{ccc}-25&-23&9\\0&0&1\\-5&-4&3\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-25%26-23%269%5C%5C0%260%261%5C%5C-5%26-4%263%5Cend%7Barray%7D%5Cright%5D)
3. Expand along the row 2: (See attached picture).
We get that the answer is 15. The determinant is 15.
Answer:
a) tan = 15/8
b) csc = 17/15
d) sec = 17/8
Step-by-step explanation:
Let me know if this is right Please :(
hope this helps :)
Answer:
362=271w
Step-by-step explanation:
If theres a letter(variable) beside a number it means mutiplication.
Hope this helps!
