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
Answer:
b = 
Step-by-step explanation:
Since the triangle is a right angled triangle, the appropriate trigonometric function can be applied to determine the value of b.
Thus, to determine the value of b;
Sin θ = 
Sin b = 
=
= 0.38462
⇒ b = 
0.38462
= 22.6202
b =
The measure of angle E (= b) is .
=
Answer:
See below
Step-by-step explanation:
Do you mean -12(x+5)=-10?
Divide both sides by -12 -> x+5=10/12
Subtract 5 on both sides -> x=10/12-5 -> x=-4 1/6
So x=-4 1/6
Let me know if this wasn't the right equation
Answer:
zero
Step-by-step explanation:
1/2 feet is less than 3/4 feet, so is insufficient length for even one propeller. No propellers can be cut from the board.
Answer:
4.2 grams in total
Step-by-step explanation:
<h2>
Remember to line up the decimal point when adding numbers that contain decimals.</h2>
3.7
+0.5
_______
4.2
