All categories

2 years ago

How can you write the expression 7(b – 2) in words?

Mathematics

2 answers:

brilliants [131]2 years ago

8 0

The answer is the product of 7 and the difference of b and - 2

lorasvet [3.4K]2 years ago

4 0

Seven times the difference of b and 2.

You might be interested in

when 1580 is divided into 13 equal parts, the remainder is 7. What is the correct way to write the quotient

Alisiya [41]

_121_ R7 or 121 7/13
13)1580
13
28
26
20
13
7

5 0

2 years ago

Read 2 more answers

Rational number 3 by 40 is equals to

kkurt [141]

Answer:

6/80, 9/120, 12/160 etc

8 0

2 years ago

Read 2 more answers

Find the equation of the line which passes through (−2, 3) and the point of intersection of the lines x + 2y=0 and 2x − y − 12=0

Alik [6]

Answer: y = 0.794*x + 4.588

Step-by-step explanation:

A linear relationship can be written as:

y = a*x + b

where a is the slope and b is the y-axis intercept.

For a line that passes through the points (x1, y1) and (x2, y2), the slope can be written as:

a = (y2 - y1)/(x2 - x1).

In this case the points are:

(-2, 3) and the intersection of the lines:

x + 2y = 0

2x - y - 12 = 0

To find the intersection of those lines, we can first isolate one variable in one side of each equality, i will isolate the variable y.

y = -x/2

y = 2x - 12

Now we can write:

-x/2 = 2x - 12

Solving this we can find the value of x at which both lines intersect.

2x + x/2 = 12

(5/2)*x = 12

x = 12*(2/5) = 4.8

Now we evaluate one of the lines in that point and get:

y = -4.8/2 = -2.4

Then these lines intersect at the point (4.8, -2.4)

Now we can find the slope of our equation.

a = (-2.4 - 3)/(4.8 - (-2)) = 0.794

then we have:

y = 0.794*x + b

And we know that when x = -2, y = 3

then:

3 = 0.794*-2 + b

3 + 1.588 = b = 4.588

Then the equation is:

y = 0.794*x + 4.588

3 0

2 years ago

Read 2 more answers

A math teacher tells her students that eating a healthy breakfast on a test day will help their brain function and perform well

kogti [31]

Answer:

Step-by-step explanation:

Hello!

To test the claim that eating a healthy breakfast improves the performance of students on their test a math teacher randomly asked 46 students what did they have for breakfast before they took the final exam and classified them as:

<u>Group 1</u>: Ate healthy breakfast

X₁: Number of students that ate a healthy breakfast before the exam and earned 80% or higher.

n₁= 26

<u>Group 2: </u>Did not eat healthy breakfast

X₂: Number of students that did not eat a healthy breakfast before the exam and earned 80% or higher.

n₂= 20

After the test she counted the number of students that got 80% or more in the test for each group obtaining the following sample proportions:

p'₁= 0.50

p'₂= 0.40

The parameters of study are the population proportions, if the claim is true then p₁ > p₂

And you can determine the hypotheses as

H₀: p₁ ≤ p₂

H₁: p₁ > p₂

α: 0.05

$Z= \frac{(p'_1-p'_2)-(p_1-p_2)}{\sqrt{p'(1-p')[\frac{1}{n_1} +\frac{1}{n_2}] } } }$ ≈N(0;1)

pooled sample proportion: $p'= \frac{x_1+x_2}{n_1+n_2} =\frac{13+8}{46} = 0.46$

$Z_{H_0}= \frac{(0.5-0.4)-0}{\sqrt{0.46(1-0.46)[\frac{1}{26} +\frac{1}{20}] } } }= 0.67$

p-value: 0.2514

The decision rule is:

If p-value ≤ α, reject the null hypothesis.

If p-value > α, do not reject the null hypothesis.

The p-value: 0.2514 is greater than the significance level 0.05, the test is not significant.

At a 5% significance level you can conclude that the population proportion of math students that obtained at least 80% in the test and had a healthy breakfast is equal or less than the population proportion of math students that obtained at least 80% in the test and didn't have a healthy breakfast.

So having a healthy breakfast doesn't seem to improve the grades of students.

I hope this helps!

5 0

2 years ago

Jeremy analyses one of his parachute jumps.

NikAS [45]

Answer:

A.) Acceleration = 4.6 m/s^2

B.) Average speed = 47 m/s

Step-by-step explanation:

A.) From the graph, at t = 10s,

Velocity V = 46 m/s

Acceleration a = (change in V)/ time t

a = (46 - 0)/10

a = 46/10 = 4.6 m/s^2

B.) If we estimate the speed at 5 seconds intervals, then we have

Average speed = (36 + 46 + 49 + 50 + 50 +50 + 50) ÷ 7

Average speed = 331/7 = 47.29 m/s

Average speed = 47 m/s

5 0

2 years ago