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3 years ago

Which expression is equivalent to –21.8 – (–18.3)?

Mathematics

2 answers:

nekit [7.7K]3 years ago

8 0

Answer:

A.-21.8+18.3

shepuryov [24]3 years ago

5 0

-21.8+18.3
or 18.3-21.8
or the answer which is -3.5

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A = 4 units B= 3 units C= 3.5. D= 5 units

aliya0001 [1]

D would be the correct answer.

Explanation

a^2+b^2=c^2

4^2+3^2=c^2

16+9

25 units

4 0

3 years ago

Demonstrate two different ways to solve the equation 5^(2x+1) = 25.

Tanzania [10]

Answer:

Step-by-step explanation:

Method 1: Taking the log of both sides...

So take the log of both sides...

5^(2x + 1) = 25

log 5^(2x + 1) = log 25 <-- use property: log (a^x) = x log a...

(2x + 1)log 5 = log 25 <-- distribute log 5 inside the brackets...

(2x)log 5 + log 5 = log 25 <-- subtract log 5 both sides of the equation...

(2x)log 5 + log 5 - log 5 = log 25 - log 5

(2x)log 5 = log (25/5) <-- use property: log a - log b = log (a/b)

(2x)log 5 = log 5 <-- divide both sides by log 5

(2x)log 5 / log 5 = log 5 / log 5 <--- this equals 1..

2x = 1

x=1/2

Method 2

5^(2x+1)=5^2

2x+1=2

2x=1

x=1/2

3 0

3 years ago

A construction company built a scale model of a building. The model was built using a scale of 3 inches = 32 feet. If the buildi

Vlad1618 [11]

Let x represent the height of the model.

We have been given that a construction company built a scale model of a building. The model was built using a scale of 3 inches = 32 feet. We are asked to find the height of the model, if the building is expected to be 200 feet tall.

We will use proportions to solve our given problem as:

$\frac{\text{Model height}}{\text{Actual height}}=\frac{\text{Model length}}{\text{Actual length}}$

Upon substituting our given values, we will get:

$\frac{x}{200\text{ ft}}=\frac{3\text{ in}}{\text{32 ft}}$

$\frac{x}{200\text{ ft}}\times 200\text{ ft}=\frac{3\text{ in}}{\text{32 ft}}\times 200\text{ ft}$

$x=3\text{ in}\times 6.25$

$x=18.75\text{ in}$

Therefore, the model will be 18.75 inches tall.

7 0

3 years ago

In the reaction 2K + Cl2 → 2KCI, the species

jonny [76]

Answer:B

Step-by-step explanation:

7 0

3 years ago

How do i solve the question in the image provided ?

Mars2501 [29]

Answer:

0.19+0.46i and 0.19-0.46i

Step-by-step explanation:

$\neq (-b+\sqrt{b^2-4ac} )/2a\\and\\(-b-\sqrt{b^2-4ac} )/2a\\\\a=8\\b=3\\c=2\\(-3+\sqrt{3^2-4*8*2} )/(2*8)\\= - 0.1875+0.463512i\\(-3-\sqrt{3^2-4*8*2} )/(2*8) = -0.1875-0.463512i$

hope its right

6 0

3 years ago