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3 years ago

11

Identify the constant term in this expression. 25x + 9y + 20 + 2y

1 answer:

kvv77 [185]3 years ago

7 0

20

Constant in a mathematical expression is a term whose value never changes.
The terms with x and y will vary based on the variable x and or y.

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Thank you guys for helping me I know I'm being annoying

Ierofanga [76]

A² + b² = c²

c² = 4² + 6.5²

c² = 58.25

c = 7.63

Perimeter = 4 + 6.5 + 7.63 = 18.13 units.

Perimeter after the increase in scale = 18.13 x 4 = 72.52 units.

Answer: 72.52 units

8 0

3 years ago

Some types of algae have the potential to cause damage to river ecosystems. Suppose the accompanying data on algae colony densit

Phantasy [73]

Answer:

$y=-2.95836 x +234.56159$

Step-by-step explanation:

We assume that th data is this one:

x: 50, 55, 50, 79, 44, 37, 70, 45, 49

y: 152, 48, 22, 35, 43, 171, 13, 185, 25

a) Compute the equation of the least-squares regression line. (Round your numerical values to five decimal places.)For this case we need to calculate the slope with the following formula:

$m=\frac{S_{xy}}{S_{xx}}$

Where:

$S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i)}{n}$

$S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}$

So we can find the sums like this:

$\sum_{i=1}^n x_i =50+ 55+ 50+ 79+ 44+ 37+ 70+ 45+ 49=479$

$\sum_{i=1}^n y_i =152+ 48+ 22+ 35+ 43+ 171+ 13+ 185+ 25=694$

$\sum_{i=1}^n x^2_i =50^2 + 55^2 + 50^2 + 79^2 + 44^2 + 37^2 + 70^2 + 45^2 + 49^2=26897$

$\sum_{i=1}^n y^2_i =152^2 + 48^2 + 22^2 + 35^2 + 43^2 + 171^2 + 13^2 + 185^2 + 25^2=93226$

$\sum_{i=1}^n x_i y_i =50*152+ 55*48+ 50*22+ 79*35+ 44*43+ 37*171+ 70*13+ 45*185+ 49*25=32784$

With these we can find the sums:

$S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}=26897-\frac{479^2}{9}=1403.556$

$S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i)}=32784-\frac{479*694}{9}=-4152.22$

And the slope would be:

$m=-\frac{-4152.222}{1403.556}=-2.95836$

Nowe we can find the means for x and y like this:

$\bar x= \frac{\sum x_i}{n}=\frac{479}{9}=53.222$

$\bar y= \frac{\sum y_i}{n}=\frac{694}{9}=77.111$

And we can find the intercept using this:

$b=\bar y -m \bar x=77.1111111-(-2.95836*53.22222222)=234.56159$

So the line would be given by:

$y=-2.95836 x +234.56159$

7 0

2 years ago

Which point is on the graph of f(x) = 2 • 5x?

Inessa [10]

Answer:

1, 10

Step-by-step explanation:

6 0

2 years ago

Read 2 more answers

A truck traveled 144 miles on 12 gallons of diesel fuel. At

Otrada [13]

Answer:

60 gallons

Step-by-step explanation:

144/12 = 12 mi/gal

720/12 = 60

7 0

2 years ago

Read 2 more answers

One number is seven more than twice another . If their sum is decreased my ten the result is twelve. Find the numbers

Rainbow [258]

Answer:

5, 17

Step-by-step explanation:

For this problem, you need to create a system of equations.

We can name one number x and the other y.

First equation: 2x + 7 = y

Second equation: x + y - 10 = 12, or x + y = 22.

We know y = 2x + 7, so we can substitute that into the second equation.

x + 2x + 7 = 22.

3x = 15

x = 5.

Plug x back into the first equation:

2 · 5 + 7 = y.

y = 10 + 7

y = 17.

3 0

3 years ago