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4 years ago

Each week samantha can pay as much as $15 for her school lunch.write an inequality showing how much Samantha spends on lunch.

Mathematics

2 answers:

kykrilka [37]4 years ago

7 0

Answer:

x<15

Step-by-step explanation:

Let <em>x</em> be the amount of money Samantha can spend.

Samantha can only pay up to 15 dollars. That means that her lunch has to cost less than 15 dollar. Less than 15 can be writen as x<15.

netineya [11]4 years ago

3 0

Answer:

15x5

Step-by-step explanation:

You might be interested in

In a volcano, erupting lava flows continuously through a tube system about 15 kilometers to the sea. Assume a lava flow speed o

koban [17]

9514 1404 393

Answer:

30 hours

Step-by-step explanation:

The relation between time, speed, and distance is ...

time = distance/speed

time = (15 km)/(0.5 km/h) = 30 h

It takes 30 hours for the lava to reach the sea.

5 0

3 years ago

The points obtained by students of a class in a test are normally distributed with a mean of 60 points and a standard deviation

Paraphin [41]

Answer:

0.13% of students have scored less than 45 points

Step-by-step explanation:

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this problem, we have that:

$\mu = 60, \sigma = 5$

About what percent of students have scored less than 45 points?

This is the pvalue of Z when X = 45. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{45 - 60}{5}$

$Z = -3$

$Z = -3$ has a pvalue of 0.0013

0.13% of students have scored less than 45 points

3 0

4 years ago

Please help me with this problem

My name is Ann [436]

Answer:

$6A- 8B = \left[\begin{array}{ccc}56&50&-14\\-126&92&62\\-78&26&2\end{array}\right]$

Option A is correct.

Step-by-step explanation:

$A=\left[\begin{array}{ccc}-4&-1&-9\\-9&6&9\\-1&-1&3\end{array}\right] \\B=\left[\begin{array}{ccc}-10&-7&-5\\9&-7&-1\\9&-4&2\end{array}\right]$

We need to find 6A - 8B

Multiply matrix A with 6 and matrix B with 8 and then subtract 6A - 8B

$6A=\left[\begin{array}{ccc}-24&-6&-54\\-54&36&54\\-6&-6&18\end{array}\right] \\8B=\left[\begin{array}{ccc}-80&-56&-40\\72&-56&-8\\72&-32&16\end{array}\right]\\6A - 8B =\left[\begin{array}{ccc}-24-(-80)&-6-(-56)&-54-(-40)\\-54-(72)&36-(-56)&54-(-8)\\-6-(72)&-6-(-32)&18-(16)\end{array}\right] \\6A - 8B =\left[\begin{array}{ccc}-24+80&-6+56&-54+40\\-54-72&36+56&54+8\\-6-72&-6+32&18-16\end{array}\right] \\6A- 8B = \left[\begin{array}{ccc}56&50&-14\\-126&92&62\\-78&26&2\end{array}\right]$

So, $6A- 8B = \left[\begin{array}{ccc}56&50&-14\\-126&92&62\\-78&26&2\end{array}\right]$

Option A is correct.

3 0

3 years ago

In planning her retirement, Liza deposits some money at 2.5% interest, with twice as much deposited at 4.5%. Find the amount dep

Harlamova29_29 [7]

Let us assume $x is deposit at 2.5% interest.

At the rate 4.5% deposited amount is twice of the amount deposited at 2.5%.

Therefore, at the rate 4.5% deposited amount = $2x.

Total interest earned by both different deposited amount at the rate 2.5% and at the rate 4.5% = $1150.

We can setup an eqation now,

Interest earned on $x at 2.5% + interest earned on $2 at 4.5% = $1150.

2.5% of x + 4.5% of 2x = 1150

Percentage could be written in decimals by dividing by 100.

Therefore, 2.5% = 2.5 /100= 0.025 and 4.5% = 4.5/100 = 0.045.

We could rewrite above equation as,

0.025*x + 0.045 * 2x = 1150

0.025x + 0.09x =1150

Adding 0.025x + 0.09x, we get 0.115x.

So, 0.115x=1150.

Dividing both sides by 0.115.

0.115x/0.115=1150/0.115.

x= $1000.

2x= 2* 1000= $2000

Therefore,

$1000 deposited at 2.5% and $2000 deposited at 4.5%.

7 0

4 years ago

Find, correct to the nearest degree, the three angles of the triangle with the given ven

Scrat [10]

9514 1404 393

Answer:

∠CAB = 86°

∠ABC = 43°

∠BCA = 51°

Step-by-step explanation:

This can be done a couple of different ways (as with most math problems). We can use the distance formula to find the side lengths, then the law of cosines to find the angles. Or, we could use the dot product. In the end, the math is about the same.

The lengths of the sides are given by the distance formula.

AB² = (4-1)² +(-3-0)² +(0-(-1)) = 16 +9 +1 = 26

BC² = (1-4)² +(2-(-3))³ +(3-0)² = 9 +25 +9 = 43

CA² = (1-1)² +(0-2)² +(-1-3)² = 4 +16 = 20

From the law of cosines, ...

∠A = arccos((AB² +CA² -BC²)/(2·AB·CA)) = arccos((26 +20 -43)/(2√(26·20)))

∠A = arccos(3/(4√130)) ≈ 86°

∠B = arccos((AB² +BC² -AC²)/(2·AB·BC)) = arccos((26 +43 -20)/(2√(26·43)))

∠B = arccos(49/(2√1118)) ≈ 43°

∠C = arccos((BC² +CA² -AB²)/(2·BC·CA)) = arccos((43 +20 -26)/(2√(43·20)))

∠C = arccos(37/(4√215)) ≈ 51°

The three angles are ...

∠CAB = 86°

∠ABC = 43°

∠BCA = 51°

_____

<em>Additional comment</em>

This sort of repetitive arithmetic is nicely done by a spreadsheet.

6 0

3 years ago