All categories

3 years ago

Expand the expression 3(7 + x)

Mathematics

1 answer:

Gre4nikov [31]3 years ago

3 0

Answer:

3x + 21 or 21 + 3x

Step-by-step explanation:

Remark

This is an example of the distributive property. Of all the fundamental rules used in solving equations, this is likely the most important, at least at beginning levels.

Solution

What this is saying is two things.

1. you must multiply both terms on either side of the + sign by the factor outside the brackets.

2. You must not destroy a plus (or minus) sign unless the two terms inside the brackets are exactly the same.

3(7 + x) The terms are not the same, so your answer must have a plus sign

Left side of the plus: 3*7

Right side of the plus: 3 * x

The answer then is 21 + 3x

It is more commonly written as 3x + 21

You might be interested in

H(x) = 1/3x - 1 if h (15)

dalvyx [7]

Answer:

(

∘

)

(

)

is known as a composite function. Here's how composite functions work:

let's say that

. Your function

(

)

(

)

now produces a

output of

, since

(

)

(

)

. Within a composite function, the y-value of one function becomes the x-value of the next, like so:

(

)

⇒

(

)

⇒

(

)

Therefore,

(

∘

)

(

)

Based on this, to find the function for

(

∘

)

(

)

(combined from right to left, by the way), simply replace

(

)

with the function

(

)

, and replace

(

)

with the function of

(

∘

)

(

)

, to get

(

∘

)

(

)

This, simplified, is equal to

, and therefore

(

∘

)

(

)

(

)

Hope that helps!

5 0

3 years ago

The length of Chen’s office is 15.5 feet and the width is 7.8 feet. Use the formula P = 2ℓ + 2w to find the perimeter of the off

zepelin [54]

46.6 feet

Step-by-step explanation:

P = 2ℓ + 2w

P = 2(ℓ + w)

P = 2(15.5 + 7.8)

P = 2(23.3)

P = 46.6 feet

5 0

3 years ago

The sum of the digits of a two-digit number is 11. When the digits are reversed, the new number is 27 more than the original num

Gwar [14]

Answer: 47

Step-by-step explanation: To solve this problem, let's use t to represent our tens digit and u to represent our units digit so that the value of our number can be represented as 10t + u.

If we represent the value of our number as 10t + u, the value of the number with the digits reversed can be represented as 10u + t.

Since the first sentence states that the sum of the digits of a two-digit number is 11, that's t + u = 11.

Reading through our second sentence, when the digits are reversed, the new number is 27 more than the original number, that's 10u + t "is" which means equals 27 more than the original number that's 10t + u + 27.

So 10t + u = 10t + u + 27.

Before solving this system however, let's rearrange our second equation so that the t's and u's are on the same side by subtracting 10t and u from both sides to get 9u - 9t = 27 and when we rewrite our first equation above it, instead of writing it as t + u = 11, let's write it as t + u = 11 so that our u's and t's will match up in the system.

To solve this system, let's use addition so multiply the top equation by 9 to get 9u + 9t = 99 and 9u - 9t = 27 so that when we add the equations together the t's cancel and we get 18u = 126. Dividing both sided by 18, u = 7.

To find t, plug 7 back in for u in our first equation to get t + 7 = 11. Subtract 7 from both sides and t = 4.

Since our tens digit is 4 and our units is 7, our number must be 47.

I have also attached my work on a whiteboard.

5 0

4 years ago

Read 2 more answers

A professor has noticed that, even though attendance is not a component of the final grade for the class, students that attend r

andrew11 [14]

Answer:

A) 57%

B) 16%

C) 53%

D) 57%

Step-by-step explanation:

Let R1 be students that attend class regularly

R2 be students that don't attend class regularly

A be students that receives A's in class

A) From the question A/R1 =57%

P(A/R1) = 0.57

B) From the question students that receive As that does not attend lectures regularly =16%

C) P(R2) = 1 -0.57 = 0.43

P(A) = P(A/R1) × P(R1) + P(A/R2)×P(R2)

P(A) = (0.57× 0.81) + (0.16×0

43)

P(A) = 0.46 + 0.0688= 0.53

The overall percentage that recieved A's = 53%

D) 57% recieved A's given that they attend class regularly.

4 0

3 years ago

The students who attend Memorial High School have a wide variety of extra-curricular activities to choose from in the after-scho

ladessa [460]

Answer:

0.16

Step-by-step explanation:

I took the test

6 0

3 years ago