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1 year ago

8

What is -2(-y) in expanded form

1 answer:

damaskus [11]1 year ago

4 0

Answer:

2y

Step-by-step explanation:

$(-2)(-y) = (-1)(2)(-1)(y) = (-1)^2\ccdot 2y = 2y$

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PLEASE HELP ILL MARK BRAINLIEST !!!

Alexus [3.1K]

Answer:

a) the common difference is 20

b) $x_8=115 , x_{12}=195$

c) the common difference is -13

d) $a_{12}=52, a_{15}=13$

Step-by-step explanation:

a) what is the common difference of the sequence xn

Looking at the table, we get x_3=16, x_4=36 and x_5= 56

Deterring the common difference by subtracting x_4 from x_3 we get

36-16 =20

So, the common difference is 20

b) what is x_8? what is x_12

The formula used is: $x_n=x_1+(n-1)d$

We know common difference d= 20, we need to find $x_1$

Using $x_3=16$ we can find $x_1$

$x_n=x_1+(n-1)d\\x_3=x_1+(3-1)d\\15=x_1+2(20)\\15=x_1+40\\x_1=15-40\\x_1=-25$

So, We have $x_1 = -25$

Now finding $x_8$

$x_n=x_1+(n-1)d\\x_8=x_1+(8-1)d\\x_8=-25+7(20)\\x_8=-25+140\\x_8=115$

So, $\mathbf{x_8=115}$

Now finding $x_{12}$

$x_n=x_1+(n-1)d\\x_{12}=x_1+(12-1)d\\x_{12}=-25+11(20)\\x_{12}=-25+220\\x_{12}=195$

So, $\mathbf{x_{12}=195}$

c) what is the common difference of the sequence $a_m$

Looking at the table, we get a_7=104, a_8=91 and a_9= 78

Deterring the common difference by subtracting a_7 from a_8 we get

91-104 =-13

So, the common difference is -13

d) what is a_12? what is a_15?

The formula used is: $a_n=a_1+(n-1)d$

We know common difference d= -13, we need to find $a_1$

Using $a_7=104$ we can find $x_1$

$a_n=a_1+(n-1)d\\a_7=a_1+(7-1)d\\104=a_1+7(-13)\\104=a_1-91\\a_1=104+91\\a_1=195$

So, We have $a_1 = 195$

Now finding $a_{12}$ , put n=12

$a_n=a_1+(n-1)d\\a_{12}=a_1+(12-1)d\\a_{12}=195+11(-13)\\a_{12}=195-143\\a_{12}=52$

So, $\mathbf{a_{12}=52}$

Now finding $a_{15}$ , put n=15

$a_n=a_1+(n-1)d\\a_{15}=a_1+(15-1)d\\a_{15}=195+14(-13)\\a_{15}=195-182\\a_{15}=13$

So, $\mathbf{a_{15}=13}$

5 0

3 years ago

A sample of men's heights was taken and the mean was 68.8 inches. The standard deviation is 2.8 inches. What percent of the men

jarptica [38.1K]

Answer:

87.29%

Step-by-step explanation:

Given: Mean= 68.8 inches

Standard deviation= 2.8 inches

Now, finding the percent of the men in the sample were greater than 72 inches.

We know, z-score= $\frac{x-mean}{standard\ deviation}$

z-score= $\frac{72-68.8}{2.8}$

⇒ z-score= $\frac{3.2}{2.8} = 1.14$

∴ z-score= 1.14

Next, using normal distribution table to find percentage.

Coverting 0.8729 into percentage= $0.8729\times 100$

We get the percentage as 87.29%

Hence, 87.29% of the men in the sample were greater than 72 inches.

6 0

3 years ago

I don't get this pls help

dmitriy555 [2]

Answer:

d, e

Step-by-step explanation:

The applicable rules of exponents are ...

(a^b)(a^c) = a^(b+c)

a^-b = 1/a^b

__

In this case, it means the product is ...

(6^1)(6^0)(6^-3) = 6^(1+0-3) = 6^-2 = 1/6^2 = 1/36

__

The 6 without an exponent is equivalent to 6^1, an exponent of 1.

The sum of the exponents is -2.

Add the exponents to simplify the expression.

The value of the expression is 1/36.

An equivalent is any expression that results in 6^-2. One such is (6^5)(6^-7).

__

Only the last two choices, d and e, apply.

3 0

3 years ago

A triangle has a perimeter of 165 cm. The first side is 65 cm less than twice the second side. The third side is 10 cm less than

Neko [114]

Answer:A triangle has a perimeter of 165 cm. The first side is 65 cm less than twice the second side. The third side is 10 cm less than the second side. Write and solve an equation to find the length of each side of the triangle.

The sides can be found by taking the square root of the area. , where = side. . So the length of a side is 6.3 cm.

Step-by-step explanation:

3 0

2 years ago

Find the area of the circle. Round your answer to the nearest hundredth 3in

FrozenT [24]

Answer:

28.26 square inches

Step-by-step explanation:

Formula for area of a circle:

$A=\pi r^2$

Radius is 3.

$A= \pi (3)^2\\A=\pi 9$

Use 3.14 for pi:

$A = 3.14 * 9 = 28.26\\A=28.26$

The area should be 28.26 square inches.

4 0

2 years ago