Solving systems of equations by substitution -2x-3(6-11)=-7

Mathematics

1 answer:

Papessa [141]3 years ago

3 0

Answer:

Step-by-step explanation:

Simplify both sides of the equation.

Subtract 15 from both sides.

Divide both sides by -2.

x = 11

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Solve for b. 2/3 b + 5 = 20 - b

Arisa [49]

Answer:

b = 9

Step-by-step explanation:

Step 1: Add b on both sides (Addition Equality)

5/3b + 5 = 20

Step 2: Subtract 5 on both sides (Subtraction Equality)

5/3b = 15

Step 3: Divide both sides by 5/3 (Division Equality)

b = 9

6 0

2 years ago

The test scores on a 100-point test were recorded for 20 students:71 93 91 86 7573 86 82 76 5784 89 67 62 7277 68 65 75 84a. Can

Dafna11 [192]

Answer: a. Yes

b. mean = 76.65

standard deviation = 10.04

c. 76.65 ± 4.4

Step-by-step explanation:

a. Stem and leaf Plot shows the frequencies with which classes of value occur. To create this plot, we divide the set of numbers into 2 columns: stem, the left column, which contains the tens digits; leaf, the right column, which contains the unit digits.

Normal distribution is a type of distribution: it's a bell-shaped, symmetrical, unimodal distribution.

A stem and leaf plot displays the main features of the distribution. If turned on its side, we can see the shape of the data.

The figure below shows the stem and leaf plot of the 100-point test score. As we can see, when turned, the plot resembles bell-shaped distribution. So, this test scores were selected from a normal population.

b. Mean is the average number of a data set. It is calculated as the sum of all the data divided by the quantity the sample has:

mean = $\frac{\Sigma x}{n}$