All categories

3 years ago

Please help mee 3f + 4(2f - 5)

1 answer:

8 0

11f-20
Explanation:
Use the distributive property to distribute the 4 to the values in the parenthesis
3f+8f-20

Then add your like terms to get your final answer
11f-20

You might be interested in

You bought a boat for $10,000. You have owned it for one year, and it is now worth $8,500. What is the percent decrease in your

Ede4ka [16]

Answer:

15%

Step-by-step explanation:

You find it by taking 10,000 and subtracting 8,500 and get $1,500. Now take $1500 and divide by the actual amount 10,000 and get 15%

5 0

3 years ago

Help!! 50 points and brainliest!

Viktor [21]

Answer:

Second choice:

$x=2t$

$y=4t^2+4t-3$

Fifth choice:

$x=t+1$

$y=t^2+4t$

Step-by-step explanation:

Let's look at choice 1.

$x=t+1$

$y=t^2+2t$

I'm going to subtract 1 on both sides for the first equation giving me $x-1=t$ . I will replace the $t$ in the second equation with this substitution from equation 1.

$y=(x-1)^2+2(x-1)$

Expand using the distributive property and the identity $(u+v)^2=u^2+2uv+v^2$ :

$y=(x^2-2x+1)+(2x-2)$

$y=x^2+(-2x+2x)+(1-2)$

$y=x^2+0+-1$

$y=x^2$

So this not the desired result.

Let's look at choice 2.

$x=2t$

$y=4t^2+4t-3$

Solve the first equation for $t$ by dividing both sides by 2:

$t=\frac{x}{2}$ .

Let's plug this into equation 2:

$y=4(\frac{x}{2})^2+4(\frac{x}{2})-3$

$y=4(\frac{x^2}{4})+2x-3$

$y=x^2+2x-3$

This is the desired result.

Choice 3:

$x=t-3$

$y=t^2+2t$

Solve the first equation for $t$ by adding 3 on both sides:

$x+3=t$ .

Plug into second equation:

$y=(x+3)^2+2(x+3)$

Expanding using the distributive property and the earlier identity mentioned to expand the binomial square:

$y=(x^2+6x+9)+(2x+6)$

$y=(x^2)+(6x+2x)+(9+6)$

$y=x^2+8x+15$

Not the desired result.

Choice 4:

$x=t^2$

$y=2t-3$

I'm going to solve the bottom equation for $t$ since I don't want to deal with square roots.

Add 3 on both sides:

$y+3=2t$

Divide both sides by 2:

$\frac{y+3}{2}=t$

Plug into equation 1:

$x=(\frac{y+3}{2})^2$

This is not the desired result because the $y$ variable will be squared now instead of the $x$ variable.

Choice 5:

$x=t+1$

$y=t^2+4t$

Solve the first equation for $t$ by subtracting 1 on both sides:

$x-1=t$ .

Plug into equation 2:

$y=(x-1)^2+4(x-1)$

Distribute and use the binomial square identity used earlier:

$y=(x^2-2x+1)+(4x-4)$

$y=(x^2)+(-2x+4x)+(1-4)$

$y=x^2+2x+-3$

$y=x^2+2x-3$ .

This is the desired result.

3 0

3 years ago

Read 2 more answers

What is the value of x?

Ksju [112]

Answer:

if we are finding the perimeter it would be x = 24

but if it is area it would be x = 480

Step-by-step explanation:

3 0

2 years ago

Help please anyoneee

DENIUS [597]

Answer:

here's the answer to your question

5 0

3 years ago

George the Pigeon travels the same distance of 72 miles

NNADVOKAT [17]

Answer:

The speed of George the Pigeon in still air = 21 miles/hr

The speed of air = 3 miles/hr

Step-by-step explanation:

Let the speed of George the Pigeon in still air = $u$ miles/hr

Let the speed of air = $v$ miles/hr

Distance traveled = 72 miles

Relative speed against the wind = $(u-v)$ miles/hr

Time taken against the wind = 4 hours

Relative speed with the wind = $(u+v)$ miles/hr

Time taken against the wind = 3 hours

Using the formula:

$Speed = \dfrac{Distance}{Time}$

$u-v=\dfrac{72}{4}\\\Rightarrow u-v=18 ..... (1)$

$u+v=\dfrac{72}{3}\\\Rightarrow u+v=24 ..... (2)$

Adding (1) and (2):

$2u=42\\\Rightarrow u = 21\ miles/hr$

By equation (1):

$v = 21-18\\\Rightarrow v = 3\ miles/hr$

Therefore, the answer is:

The speed of George the Pigeon in still air = 21 miles/hr

The speed of air = 3 miles/hr

8 0

2 years ago