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2 years ago

Explain how you can tell if the expressions 7x – 4 and 6x – 4 – x are equivalent.

Mathematics

1 answer:

Alina [70]2 years ago

8 0

Hey there!

Combine Like Terms and see if the expressions are equivalent or not.

6x-4-x

6x-x-4

5x-4

Is 5x-4 equivalent to 7x-4? No.

Hope everything is clear.

Let me know if you have any questions!

Always remember: Knowledge is power!

You might be interested in

Write a function to represent the set of ordered pairs. {(2, 6), (3, 21), (4, 42), (5, 69)} a) f(x) = 3x b) f(x) = x + 4 c) f(x)

Ugo [173]

We are given order pairs : (2, 6), (3, 21), (4, 42), (5, 69)

The correct option is D) f(x) = 3x^2 - 6.

If we plug x=2 we get

f(2) = 3(2)^2 - 6 = 3(4) -6 = 12-6 =6. Represents (2,6)

If we plug x=3 we get

f(3) = 3(3)^2 - 6 = 3(9) -6 = 27-6 =21 Represents (4,21)

If we plug x=4 we get

f(4) = 3(4)^2 - 6 = 3(16) -6 = 48-6 =42. Represents (4,42)

If we plug x=5 we get

f(5) = 3(5)^2 - 6 = 3(25) -6 = 75-6 =69. Represents (5,69)

Therefore, D ) f(x) = 3x^2 - 6 is our correct option.

3 0

4 years ago

Add 3 feet 6 inches+8 feet 2 inches+4 inches+2 feet 5 inches. 4. In a grocery store, steak costs $3.85 per pound. If you buy a t

AnnZ [28]

Answer:

The sum of the measurement is 14 feet 5 inches.

Hence, you will get the change of $8.45

The required sum is 46 minutes 5 seconds.

Step-by-step explanation:

Consider the provided information.

Add 3 feet 6 inches+8 feet 2 inches+4 inches+2 feet 5 inches.

In order to add the measurement add inches with inches and feet with feet as shown.

3 feet + 8 feet + 2 feet and 6 inches + 2 inches + 4 inches + 5 inches.

13 feet 17 inches

As we know 1 feet = 12 inches

Thus 17 inches can be written as: 1 feet 5 inches

Hence, 13 feet 17 inches = 14 feet 5 inches

The sum of the measurement is 14 feet 5 inches.

Part (B) In a grocery store, steak costs $3.85 per pound. If you buy a three-pound steak and pay for it with a $20 bill, how much change will you get?

Steak costs $3.85 per pound and you buy a three pound steak.

So, the cost will be:

$3.85×3=$11.55

You pay $20 so the change you will get is:

$20-$11.55=$8.45

Hence, you will get the change of $8.45

Part (C) Add 8 minutes 32 seconds+37 minutes 18 seconds+15 seconds.

In order to add the time add minutes with minutes and seconds with seconds as shown.

8 minutes+37 minutes and 32 seconds+ 18 seconds+15 seconds.

45 minutes 65 seconds

As we know 1 minute = 60 seconds

Thus 65 seconds can be written as: 1 minute 5 seconds

Hence, 45 minutes 65 seconds = 46 minutes 5 seconds

The required sum is 46 minutes 5 seconds.

6 0

3 years ago

At a wedding reception, there will be 1,012 guests. A round table will seat 12 guests. How many round tables will be needed?

Whitepunk [10]

Answer:

85 tables

Step-by-step explanation:

1012 divided by 12 is 84 and 1/3. We want to have room for everyone, so we round up to 85.

3 0

3 years ago

Find the unit tangent vector T and the principal unit normal vector N for the following parameterized curve.

const2013 [10]

Answer:

$T(t) = ( -sin(t^2), cos(t^2) )\\\\N(t) = T'(t) / |T'(t) | = (-cos(t^2) , -sin(t^2))$

$T(t) =r'(t)/|r'(t)| = (2t/ \sqrt{4t^2 + 36} , -6/\sqrt{4t^2 + 36},0)$

$N(t) =T(t)/|T'(t)| = (3/(9 + t^2)^{1/2} , t/(9 + t^2)^{1/2},0)$

Step-by-step explanation:

Remember that for any curve $r(t)$

The tangent vector is given by

$T(t) = \frac{r'(t) }{| r'(t)| }$

And the normal vector is given by

$N(t) = \frac{T'(t)}{|T'(t)|}$

For this case, using the chain rule

$r'(t) = ( -10*2tsin(t^2) , 102t cos(t^2) )\\$

And also remember that

$|r'(t)| = \sqrt{(-10*2tsin(t^2))^2 + ( 10*2t cos(t^2) )^2} \\\\ = \sqrt{400 t^2*( sin(t^2)^2 + cos(t^2) ^2 })\\=\sqrt{400t^2} = 20t$

Therefore

$T(t) = r'(t) / |r'(t) | = ( -10*2tsin(t^2) , 10*2t cos(t^2) )/ 20t\\\\ = ( -10*2tsin(t^2)/ 20t , 10*2t cos(t^2) / 20t )\\= ( -sin(t^2), cos(t^2) )$

Similarly, using the quotient rule and the chain rule

$T'(t) = ( -2t cos(t^2) , -2t sin(t^2))$

And also

$|T'(t)| = \sqrt{ ( -2t cos(t^2))^2 + (-2t sin(t^2))^2} = \sqrt{ 4t^2 ( ( cos(t^2))^2 + ( sin(t^2))^2)} = \sqrt{4t^2} \\ = 2t$

Therefore

$N(t) = T'(t) / |T'(t) | = (-cos(t^2) , -sin(t^2))$

Notice that

1. $|N(t)| = |T(t) | = \sqrt{ cos(t^2)^2 + sin(t^2)^2 } = \sqrt{1} = 1$

2. $N(t)*T(T) = cos(t^2) sin(t^2 ) - cos(t^2) sin(t^2 ) = 0$

Simlarly

$r'(t) = (2t,-6,0) \\$

and

$|r'(t)| = \sqrt{(2t)^2 + 6^2} = \sqrt{4t^2 + 36}$

Therefore

$T(t) =r'(t)/|r'(t)| = (2t/ \sqrt{4t^2 + 36} , -6/\sqrt{4t^2 + 36},0)$

Then

$T'(t) = (9/(9 + t^2)^{3/2} , (3 t)/(9 + t^2)^{3/2},0)$

and also

$|T'(t)| = \sqrt{ ( (9/(9 + t^2)^{3/2} )^2 + ( (3 t)/(9 + t^2)^{3/2})^2 + 0^2 }\\= 3/(t^2 + 9 )$

And since

$N(t) =T(t)/|T'(t)| = (3/(9 + t^2)^{1/2} , t/(9 + t^2)^{1/2},0)$

6 0

3 years ago

Neeeeedd help hurry please

Alona [7]

Answer:

Step-by-step explanation:

Sslsl

6 0

3 years ago