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2 years ago

Find the product. (7−x)(x−1)=

Mathematics

2 answers:

Alexxx [7]2 years ago

5 0

Answer:

-x^2 + 8x - 7

Step-by-step explanation:

(7 - x)(x - 1)

(7 * x) + (7 * -1) + (-x * x) + (-x * -1)

7x - 7 - x^2 + x

8x - 7 - x^2

-x^2 + 8x - 7

Best of Luck!

vaieri [72.5K]2 years ago

3 0

Answer:

-x² + 8x - 7

Step-by-step explanation:

Step 1: Write expression

(7 - x)(x - 1)

Step 2: FOIL (First Outside Inside Last)

7x - 7 - x² + x

Step 3: Combine like terms

-x² + 8x - 7

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Suppose that we want to investigate whether curfews correlate with differences in grades for students in middle school. We selec

Anton [14]

Answer:

Step-by-step explanation:

Hello!

Given the variables

X: Curfew of middle school students (Categorized Yes/No)

Y: Average grade of middle school students. (Categorized: A, B, C, and D)

The objective is to test if there is an association between both variables, you have to conduct a Chi-Square test of independence.

In the null hypothesis, you state that both variables are independent vs. the alternative hypothesis that the variables are dependent.

The hypotheses for this test are:

H₀: Pij= Pi. * P.j i= (1)Yes, (2)No; j= (1)A, (2)B, (3)C, (4)D

H₁: Te variables are not independent.

α: 0.05

$X^2= sum\frac{(O_{ij}-E_{ij})^2}{E_{ij}} ~~X_{(r-1)*(c-1)}$

Where

Oij is the observed frequency for the i-row and j-column

Eij is the expected frequency for the i-row and j-column

r= number of categories in the rows

c= number of categories in the columns

$X^2_{H_0}= 1.4796703$

p-value: 0.687

The p-value is greater than the significance level, so the decision is to not reject the null hypothesis. So using a 5% significance level, you can conclude that having a curfew and the average grades of middle schoolers are two independent variables.

3 0

2 years ago

Two trains are traveling at a constant rate. Which train has the greater speed?

Contact [7]

Answer:

Train B.

Step-by-step explanation:

2 hours on Train A would be 120 miles and 2 miles on Train B would be 250 miles. The greater number (which is train B) is the one going the fastest.

Please mark me brainliest I need it! Please!

5 0

2 years ago

verify that the fucntion satisfies the three hypotheses of rolles theorem on the given interval . then find all numbers c that s

Ghella [55]

The roots of the polynomial x^3 − 2x^2 − 4x + 2 are:

x1 = 0.42801

x2 = −1.51414

x3 = 3.08613

x1 and x2 are in the desired interval [-2, 2]

f'(x) = 3x^2 - 4x - 4

so we have:

3x^2 - 4x - 4 = 0

x = ( 4 +- √(16 + 48) )/6

x_1 = -4/6 = -0.66

x_ 2 = 2

According to Rolle's theorem, we have one point in between:

x1 = 0.42801 and x2 = −1.51414

where f'(x) = 0, and that is x_1 = -0.66

so we see that Rolle's theorem holds in our function.

4 0

2 years ago

in 448 244 how is the relationship between the first pair of 4s the same as the relationship between the second pair of 4s

sineoko [7]

Well there similar because your adding 10 more or 10× since from ones to the tens is 10×

8 0

2 years ago

Read 2 more answers

At 7:00 A.M., Alicia pours a cup of tea whose temperature is 200°F. The tea starts to cool to room temperature (72°F). At 7:02 A

NeTakaya

Answer:

Part A

The most correct option is;

b. y = 128(0.989)x + 72

Part B

Ella can drink the tea after 7:22

Step-by-step explanation:

Here we have the temperature variation with time given in an exponential equation as follows;

Let the temperature at time x (in minutes) = y

Therefore, y = a × mˣ + b

Where:

b = Shift of the curve or the limit value of the decreasing exponential function as x → ∞

When y = 200, x = 0

Therefore. 200 = a × m⁰ + c = a + c

We note that c is the shift of the graph, the value upon which temperature increases = final temperature = 72°F

Hence a = 200 - 72 = 128°F

When y = 197, x = 2 minutes

Therefore, 197 = 128·m² + 72 =

m² = (197 - 72)/128 = 125/128

m = √(125/128) = 0.98821

Hence the exponential equation of cooling is presented in the following equation;

y = 128 × (0.98821)ˣ + 72

Therefore, the most correct option is b. y = 128(0.989)x + 72

Part B

When the temperature is 172°F we have;

172 = 128 × (0.989)ˣ + 72

∴ (0.989)ˣ = (172 - 72)/128 = 100/128 = 25/32

log(0.989)ˣ = log(25/32)

x·log(0.989) = log(25/32)

x = log(25/32)/log(0.989) = 22.32 minutes

Hence Ella can drink the tea after 7:22.

6 0

2 years ago