Answer:
The difference of 8 times a number r and 12 is solved for a number r and is given by 
Step-by-step explanation:
Given problem is the difference of 8 times a number r and 12
It can be written as
To simplify the above expression :
8r-12
( using addition property of equality )
(using division property of equality )
Therefore
Therefore the difference of 8 times a number r and 12 is solved for a number r and is given by
We must multiply 20% by 5 in order to reach 100%.
To find out the total number of pages in Oswaldo's book, we must multiply his 20% (65) by 5, therefore:
65 * 5 = 325 total pages
The probability to choose letter n is
. After drawing letter n there left 25 letters and the probability to choose the letter w is
. After drawing two letters n and w there left 24 letters and then the probability to choose letter b is
. After drawing three letters n, w and b there left 23 letters, so the probability to choose letter t is
.
Using the product rule for probabilities, you can obtain that
.
There are two equation:
1) From Kim
2) From Daniel
Let:
x be the cost of rolls of plain wrapping paper
y be the cost of rolls of shiny wrapping paper
Kim:
7x + 8y = 140
Daniel:
14x + 7y = 154
<u>Using elimination method:</u>
(7x + 8y = 140) * -2 (Multiplying the equation by -2)
-14x - 16y = -280
-14x -16y = -280
14x + 7y = 154
------------------------------
0x - 9y = -126
9y = 126 (Negative sign cancels from both sides)
y = 126 /9
y = 14
The cost of each shiny wrapping paper is $14.
Now solve x, you pick any two equation to solve for x.
7x + 8y = 140
7x + 8(14) = 140 (You know from above y =14)
7x + 112 = 140
7x = 28
x = 28/7
x = 4
The cost of each plain wrapping paper is $4.
Solution: (4,14)
