Let x be the cost of 1 pen
then cost of 1 notebook = x + 8.20
Let y be the number of pens Tan buys
then number of notebooks Tan buys = y/4
She spent $26 more on books than on pens which means
Cost of notebooks - Cost of pens = 26
(x + 8.20) * y/4 - xy = 26
Sinplifying it
(xy + 8.20y)/4 - xy = 26
(xy + 8.20y - 4xy)/4 = 26
8.20y - 3xy = 104
She spent $394 which means
Cost of notebooks + Cost of pens = 394
(x + 8.20) * y/4 + xy = 394
Simplifying it
(xy + 8.20y)/4 + xy = 394
(xy + 8.20y + 4xy)/4 = 394
8.20y + 5xy = 1576
Now, we have two equations,
(1) 8.20y - 3xy = 104
(2) 8.20y + 5xy = 1576
Now we need to find a third equation with either x or y as the subject of any of both the previous equations.
Let's make y the subject of (2) equation
8.20y + 5xy = 1576
y(8.20 + 5X) = 1576
(3) y = 1576/(8.20 + 5x)
Let's substitute the new value of y from (3) into (1) because we rearranged (2) to from (3)
8.20y - 3xy = 104
y(8.20 - 3x) = 104
y = 104/(8.20 - 3x)
1576/(8.20 + 5x) = 104/(8.20 - 3x)
1576 * (8.20 - 3x) = 104 * (8.20 + 5x)
12923.2 - 4728x = 852.8 + 520x
12923.2 - 852.8 = 4728x + 520x
12070.4 = 5248x
12070.4/5248 = x
x = 2.3
Now find the value of y by substituting the value of x in either equation, preferably (3)
y = 1576/(8.20 + 5x)
y = 1576/(8.20 + 5 * (2.3))
y = 80
Therefore cost of 1 notebook = x + 8.20 = 2.3 + 8.20 = $10.50
Could I see a picture of what kind of triangle it is please?
Answer: 40%
Step-by-step explanation:
Setting up an equation to solve,
25 as the denominator representing the total number of baseball games played to represent the "whole."
10 as the numerator representing the number of games the baseball games won to represent the "part" you want to calculate as a percentage.
The equation, looking like this,
10/25 = ___
after calculating the equation you get 2/5 as reduced, evaluating that in terms of percentage you get 40% as 5 represents 100% (the whole) and 2 representing 40% (the number of baseball games won)
Answer: D. (-6,2)
Step-by-step explanation:
y = x + 8
2x + y = -10
v
2x + x +8 = -10
x = -6
y = -6 + 8 ( plug in x (-6) )
y = 2
( x, y) = ( -6, 2)
Answer:
The cost would be $81.09
Step-by-step explanation:
In order to find the amount Chris will spend, start with the equation and input 100 for every x that you see.
c=0.765x +0.06(.765x)
c=0.765(100) +0.06(.765[100])
c = 76.50 + 0.06*(76.50)
c = 76.50 + 4.59
c = 81.09
