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3 years ago

Suppose a + b = 0. Which one of these expressions equals a-b?

Mathematics

2 answers:

tatyana61 [14]3 years ago

3 0

There is no attached file to look at the choices. I’m looking forward to answer your question.

storchak [24]3 years ago

3 0

For this case we have:

Given $a + b = 0$ , we want to find an expression equivalent to $a-b$ .

Let the equation $a + b = 0$ be:

Subtract -2b on both sides of the equation:

$a + b-2b = 0-2b$

Taking into account that different signs are subtracted and the sign of the major is placed:

$a-b = -2b$

Thus, an expression equivalent to $a-b$ is $-2b$ .

Answer:

-2b

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Alia has a AED 20 gift card for an online music store. All songs at the store have the same price. After Alia buys 3 songs, the

sladkih [1.3K]

Answer:

Remaining balance = AED 13.75

Step-by-step explanation:

Given that:

Amount of gift card = AED 20

Amount left after buying 3 songs = AED 16.25

Cost of 3 songs = 20 - 16.25 = AED 3.75

Cost per song = $\frac{3.75}{3}$

Cost per song = AED 1.25

Cost of 5 songs = 5(1.25) = AED 6.25

Remaining balance = 20 - 6.25 = AED 13.75

Hence,

Remaining balance = AED 13.75

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3 years ago

Solve the following inequality: –1 + 6(–1 – 3x) > –39 – 2x.

insens350 [35]

<span>–1 + 6(–1 – 3x) > –39 – 2x.
</span>-1-6-18x>-39-2x
-7-18x>-39-2x
-18x>-32-2x
-16x>-32
x<2

B. x<2

7 0

3 years ago

Read 2 more answers

A group of people were asked if they had run a red light in the last year. 315 responded "yes", and 190 responded "no".

Iteru [2.4K]

Answer:

0.624

Step-by-step explanation:

Number who have run a red light = 315

Number who haven't run a red light = 190

From the data :

The total number of people sampled = total possible outcome = (315 + 190) = 505

Selecting a person at random, probability that the selected person has run a red light :

P = required outcome / Total possible outcomes

Required outcome = Number who have run a red light = 315

P(having run a red light) = 315 / 505 = 0.624

6 0

3 years ago

A basic cellular phone plan costs $4 per month for 70 calling minutes. Additional time costs $0.10 per minute. The formula C= 4+

Harrizon [31]

Answer:

For a monthly cost of at least $7 and at most $8, you can have between 100 and 110 calling minutes.

Step-by-step explanation:

The problem states that the monthly cost of a celular plan is modeled by the following function:

$C(x) = 4 + 0.10(x-70)$

In which C(x) is the monthly cost and x is the number of calling minutes.

How many calling minutes are needed for a monthly cost of at least $7?

This can be solved by the following inequality:

$C(x) \geq 7$

$4 + 0.10(x - 70) \geq 7$

$4 + 0.10x - 7 \geq 7$

$0.10x \geq 10$

$x \geq \frac{10}{0.1}$

$x \geq 100$

For a monthly cost of at least $7, you need to have at least 100 calling minutes.

How many calling minutes are needed for a monthly cost of at most 8:

$C(x) \leq 8$

$4 + 0.10(x - 70) \leq 8$

$4 + 0.10x - 7 \leq 8$

$0.10x \leq 11$

$x \leq \frac{11}{0.1}$

$x \leq 110$

For a monthly cost of at most $8, you need to have at most 110 calling minutes.

For a monthly cost of at least $7 and at most $8, you can have between 100 and 110 calling minutes.

8 0

3 years ago

Help! I don’t get this at all !

Oxana [17]

Answer:

Step-by-step explanation:

I want to start with a quick explanation of slope/ rate of change since you say you don't get it at all. Basically it measures how fast something changes. Or, in other words, if x changes by so much, y will change by a corresponding amount.

If you look at the graph of just y=x, you can see that as x changes by 1 so does y. if you make it y=2x, will x=1 makes y=2, and x = 2 makes y = 4, so here it changes by 2. You cans ee it keeps going in that manner. Also notice these make straight lines, maybe not horizontal, but still straight diagonal lines. This is important for a constant slope.

The way slope can be describes is "rise over run" also. Which means you count how many you "rise" and divide it by how many you "run", or in other words how your y values change and your x values change. Using y = -.5x this time let's see what we get using this rise over run idea. It's usually easier to compute the "run" first, so let's say we move from 2 to 4. That makes our run 2, keep that in mind. the y values that correspond to this are -.5*2 = -1 and -.5*4 = -2 note we keep the negative signs here. Now that we have the y values what are the change in them? well to go from -1 to -2 is -1, so our change in y is -1.

As I started with the rise over run is change in y divided by change in x. we found both of those so our slope is -1/2 so negative one half. That's just an example to hopefully clear up any confusion about slope.

The first part of your question I'm not sure about. Are any numbers given at all anywhere? the y looks longer than x but we can't really say exactly how long. We can tell the slope is negative at least, since it points downward going from left to right, but I don't think we can say what the exact rate of change (slope) is.

The second part uses the first so hard to say. If you can find what the rate of change is the answer will basically be (delta y) = (rate of change)*(delta x) since rate of change = (delta y)/(delta x) since delta means "change in"

The third gives some numbers, but we would still need the rate of change. I'll give the best answer I can. I do want to say that putting slope into an equation will often be represented by the letter m.

Anyway, pretending we know what m is, the method to find the equation of y is to use the formula y - y1 = m(x - x1). x1 and y1 are the coordinates of a point that you need. And int he question they give you one. So we will plug in.

y - y1 = m(x - x1)

y - (-2.5) = m(x - 1) Then distribute that m we're pretending we know

y - (-2.5) = mx - m Then get y by itself

y = mx - m - 2.5

So once you know m you can solve everything else. If you can find something that says how long those red and blue lines are, or maybe the points they point from and to you can let me know. Hopefully this helpped though.

3 0

3 years ago