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
Given
Present investment, P = 22000
APR, r = 0.0525
compounding time = 10 years
Future amount, A
A. compounded annually
n=10*1=10
i=r=0.0525
A=P(1+i)^n
=22000(1+0.0525)^10
=36698.11
B. compounded quarterly
n=10*4=40
i=r/4=0.0525/4
A=P(1+i)^n
=22000*(1+0.0525/4)^40
=37063.29
Therefore, by compounding quarterly, she will get, at the end of 10 years investment, an additional amount of
37063.29-36698.11
=$365.18
9×8-29+30/15-15 equals 30
Answer:
y = 1/3x + 4 1/3
Step-by-step explanation:
2x - 6y = 12
First find the slope
Solve for y
Subtract 2x
2x - 6y -2x= 12-2x
-6y = -2x+12
Divide by -6
-6y/-6 =-2x/-6 +12/-6
y = 1/3 x -2
The slope is 1/3
Parallel lines have the same slope
Using the slope intercept form y = mx+b where m is the slope and b is the y intercept
y = 1/3x +b
And substituting in the point
4 = 1/3 (-1) +b
4 = -1/3 +b
Add 1/3 to each side
4 + 1/3 = b
y = 1/3x + 4 1/3
