Ronald bought a number of cds for 13$ each. What was the total amount he spent on CDs

13/78 in simplest form

hjlf

Answer:

Step-by-step explanation:

1/6

8 0

3 years ago

Read 2 more answers

Write as a polynomial. a(a+9b)^2

Alex Ar [27]

Answer: a^3+81ab^2
First, you square (a+9b) which will become (a^2+81b^2)
Then, you multiply it by a and you will get a^3+81ab^2

4 0

2 years ago

What is the equation of the quadratic graph with a focus of (1, 1) and a directrix of y = −1? PLs HELP!!

Delicious77 [7]

ANSWER
$f(x)= \frac{1}{4} {(x - 1)}^{2}$

EXPLANATION

Since the directrix is
$y = - 1$

the axis of symmetry of the parabola is parallel to the y-axis.

Again, the focus being,

$(1,1)$

also means that the parabola will open upwards.

The equation of parabola with such properties is given by,

${(x - h)}^{2} = 4p(y - k)$
where
$(h,k)$

is the vertex of the parabola.

The directrix and the axis of symmetry of the parabola will intersect at
$(1, - 1)$

The vertex is the midpoint of the focus and the point of intersection of the axis of the parabola and the directrix.

This implies that,
$h = \frac{1 + 1}{2} = 1$

and
$k = \frac{ - 1 + 1}{2} = 0$

The equation of the parabola now becomes,

$(x - 1) ^{2} = 4p(y - 0)$

$|p| = 1$

Thus, the distance between the vertex and the directrix.

This means that,

$p = - 1 \: or \: 1$

Since the parabola opens up, we choose
$p = 1$
Our equation now becomes,

${(x - 1)}^{2} = 4(1)(y - 0)$

This simplifies to
${(x - 1)}^{2} = 4y$

or

$y = \frac{1}{4} {(x - 1)}^{2}$

This is the same as,

$f(x)= \frac{1}{4} {(x - 1)}^{2}$

The correct answer is D .

4 0

3 years ago

write an expression to describe a rule for the sequence. Then find the 100th term in the sequence 3, 10, 17, 24, 31, 38, ...

blagie [28]

As we can tell, the first number is 3, so we'll have a y-intercept in our equation and overall. Secondly, we can tell it's increasing by 7 each time, so we can tell that's the rate. But, it won't just be 3+7x, if we plug 1 in, it would be 10 and not 3. We need to put in the parenthesis 3+7(x-1). If we put one in, we would receive three. Let's make sure this works.
3+7(5-1)
3+7(4)
3+28
31
31 is the fifth terms.
So the expression would be 3+7(x-1).
Let's find the 100th term.
3+7(100-1)
3+7(99)
3+693
696
So the 100th term would be 696.

3 0

3 years ago

Sandra uses her office fax machine to send fax at the rate of $0.10 per page. She decides to rent a fax machine for $80 a year.

Maksim231197 [3]

Part A:
First we define the variable to be used for the problem:
x: the number of pages that Sandra should fax
The inequality for rent is:
0.06x <= 80
Note that the price will be less than using the fax from the office, since for the same number of pages, we have:
y = 0.10x
Answer:
an inequality that can be used to calculate the number of pages that Sandra should fax in a year is:
0.06x <= 80

Part B:
0.06x <= 80
From here we clear x:
x <= 80 / 0.06
x <= 1333.33333
Nearest whole number
x <= 1333
Sandra can use the leased fax for 1333 pages and the cost will be:
1333 * 0.06 = 79.98 $
Using the office fax the cost will be:
1333 * 0.1 = 133.3 $
Answer:
By renting the sara machine, you save:
133.3-79.98 = 53.32 $

8 0

3 years ago