Answer:
20x + 18
Step-by-step explanation:
We need to use the distributive property, where we essentially take the sum of the product of the outside number with each of the inside terms.
In 7(4x - 2), 7 is the outside number and 4x and -2 are the inside numbers, so:
7(4x - 2) = 7 * 4x + 7 * (-2) = 28x - 14
In 4(2x - 8), 4 is the outside number and 2x and -8 are the inside numbers, so:
4(2x - 8) = 4 * 2x + 4 * (-8) = 8x - 32
Now, we have:
28x - 14 - (8x - 32) = 28x - 14 - 8x + 32 = 20x + 18
The answer is 20x + 18.
The number of books sold is 473.
<u>Step-by-step explanation:</u>
- The original cost of each book = $0.64
- The selling price of each book = $0.75
The difference between the original price and selling price of the book gives the profit per book.
The profit of one book = Selling price - Original price
Let,
- The total number of books be 'x'.
- The number of books sold be 'y'.
- The unsold books is 100.
- The total profit is -12 because it was gone to a loss of $12.
Therefore, the equation is formed as
total Profit = 0.75y - 0.64x
⇒ 0.75y - 0.64x = -12 --------(1)
Total books = sold books + unsold books
x = y + 100
⇒ x-y = 100 -------(2)
Substitute x= 100+y in the eq(1),
0.75y - 0.64(100+y) = -12
0.75y - 64 -0.64y = -12
0.11y = -12 +64
y = 52 / 0.11
y = 472.7
y ≅ 473
The number of book sold is 473 books.
The total number of books is (100+473) = 573 books.
Answer:
a) not proportional
b) proportional; k =
Step-by-step explanation:
a) for any proportional equation, the line must pass through the origin. The equation in a) is y = 4x + 1, and the '+1' is the y-intercept. This means that the line does not pass through the origin, so x and y cannot increase by the same amount (i.e. they are not proportional).
Another way to determine this is is to use the y = kx base. If you have an equation that fits that it's likely proportional.
Here, if the equation was only y = 4x then it'd be proportional because u can see that k = 4. This is not the equation though, and the 4x + 1 doesn't fit to the y = kx formula so it can't be proportional.
b) straight away you can see that there's no 'c' term (y = mx + c) which means the y-intercept is 0, so the line passes through the origin. While this does not immediately mean the line is proportional, you can make sure that it is by checking it fits with the y = kx equation.
y = -(3/5)x fits with y = kx, with k being -3/5
2x - y = 0
2x = y
3x - 2(2x) = -3
3x - 4x = -3
-x = -3
x = 3
2(3) = y
6 = y
Answer:
1 5/9
Step-by-step explanation: