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3 years ago

Simplify: 1. 4x−(1−2x)+(2x−7) 2. (3−0.4a)−(10−0.8a)

Mathematics

1 answer:

dem82 [27]3 years ago

7 0

Answer:1.8(x -1)

2.0.4a -7

Step-by-step explanation:

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A line contains (4,2) and (0,-1). What is the equation line?

densk [106]

The answer is B. Y= 3/4x-1

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3 years ago

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The average grain of salt is 0.0003 meters wide. Rhinovirus, which causes the common cold, is 0.00000003 meters wide. How many t

algol [13]

Answer:

$1\times 10^4\ times$

Step-by-step explanation:

Given:

Width of average grain of salt is, $w=0.0003\ m$

Width of Rhinovirus is, $W=0.00000003\ m$

Now, expressing each width in scientific notation form, we get:

$w=0.0003\ m = 3\times 10^{-4}\ m\\\\W=0.00000003\ m = 3\times 10^{-8}\ m$

Now, in order to get how many times 'W' is wider than 'w', we divide the two widths. This gives,

$\frac{W}{w}=\frac{3\times 10^{-4}\ m}{3\times 10^{-8}\ m}\\\\\frac{W}{w}=1\times 10^{-4-(-8)}=1\times 10^{-4+8}=1\times 10^4\\\\\therefore W=1\times 10^4\times w$

Therefore, the grain of salt is $1\times 10^4\ times$ wider than Rhinovirus.

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3 years ago

Water tank is being filled with water. Before water is pumped in, the water level in the tank is 12 inches high. After 20 minute

zhenek [66]

Answer:

D. H = 2.1t + 12

Step-by-step explanation:

Let us assume the t be the time in minutes

And h be the water level

Now before reaching to the equation that need to be used

before this, determine the inches per minute i.e.

= 54 inches - 12 inches

= 42 inches in 20 minutes.

Now for per minute, it would be

= 42 inches ÷ 20 minutes

= 2.1 inches per minute

After this, multiply the inches per minute with the minutes t and add the sale to the beginning value i.e. 12

So the equation is

H = 2.1t + 12

hence, the last option is correct

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2 years ago

Find the area of the composite figure below.

pashok25 [27]

Answer: D is the correct answer.

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2 years ago

Write an equation (-2, 10), (10, -14)

Brilliant_brown [7]

$\bf (\stackrel{x_1}{-2}~,~\stackrel{y_1}{10})\qquad (\stackrel{x_2}{10}~,~\stackrel{y_2}{-14}) \\\\\\ \stackrel{slope}{m}\implies \cfrac{\stackrel{rise} {\stackrel{y_2}{-14}-\stackrel{y1}{10}}}{\underset{run} {\underset{x_2}{10}-\underset{x_1}{(-2)}}}\implies \cfrac{-24}{10+2}\implies \cfrac{-24}{12}\implies -2$

$\bf \begin{array}{|c|ll} \cline{1-1} \textit{point-slope form}\\ \cline{1-1} \\ y-y_1=m(x-x_1) \\\\ \cline{1-1} \end{array}\implies y-\stackrel{y_1}{10}=\stackrel{m}{-2}[x-\stackrel{x_1}{(-2)}]\implies y-10=-2(x+2) \\\\\\ y-10=-2x-4\implies y=-2x+6$

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3 years ago