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3 years ago

Let f(x) = 4x − 3. If f(a) = 9 and f(b) = 5, then what is f(a + b) ?

1 answer:

7 0

F(x) = 4x - 3

f(a) = 4a-3

9 = 4a-3

4a = 12

a = 12 / 4

a = 3

_____________________

f(b) = 4b-3

5+3 = 4b

8 = 4b

b = 8 / 4

b = 2

___________________

f(a+b) = 4(a+b) - 3

f(a+b) = 4(3+2) - 3

f(a+b) = 4(5) - 3

f(a+b) = 20 - 3

f(a+b) = 17

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Evaluate |2x+y-3z| for x=-2, y=10, and z=3<br> How to solve?

Angelina_Jolie [31]

|2x + y - 3z|
Plug in the values
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3 years ago

Read 2 more answers

Omar has decided to purchase an $11,000 car. He plans on putting 20% down toward the purchase, and financing the rest at 4.8% in

Solnce55 [7]

Answer:

The monthly payment is $262.95

Step-by-step explanation:

* Lets explain how to solve the problem

- Omar has decided to purchase an $11,000 car

- He plans on putting 20% down toward the purchase

* Lets find the value of the 20%

∵ The principal value is $11000

∴ the value of the 20% = 20/100 × 11000 = 2200

∴ He will put $2200 down

* Lets find the balance to be paid off on installments

∴ The balance = 11000 - 2200 = 8800

- He financing the rest at 4.8% interest rate for 3 years

* Lets find the rule of the monthly payment

∵ $pmt=\frac{\frac{r}{n}[P(1+\frac{r}{n})^{nt}]}{(1+\frac{r}{n})^{nt}-1}$ , where

- pmt is the monthly payment

- P = the investment amount

- r = the annual interest rate (decimal)

- n = the number of times that interest is compounded per unit t

- t = the time the money is invested or borrowed for

∵ P = 8800

∵ r = 4.8/100 = 0.048

∵ n = 12

∵ t = 3

∴ $pmt=\frac{\frac{0.048}{12}[8800(1+\frac{0.048}{12})^{3(12)}]}{(1+\frac{0.048}{12})^{3(12)}-1}$

∴ $pmt=\frac{0.004[8800(1.004)^{36}]}{(1.004)^{36}-1}=262.95$

* The monthly payment is $262.95

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3 years ago

The diameter of a circle is 1 meter.the circumference is how many centimeters

andre [41]

Step-by-step explanation:

C= pi×d

d=.5 meters

so plug in the numbers

3.14 × .5= 1.75

circumference= 1.75 meters

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3 years ago

Write the explicit formula for the geometric sequence. Then find the fifth term in the sequence.

Blababa [14]

Sequence: -4, 8, -16

rate of increase: -16/8 = -2

If you make A1 the first term in the sequence you must use (n-1) in the explicit formula. If you go backwards in the sequence to find A0 = 2 then you would use n.

The don't have A0 = 2 listed as an option so we use A1 = -4 and (n-1) terms.

An = -4(-2)^(n-1)

Solving for the 5th term A5, use n = 5

A5 = -4(-2)^(5-1)
A5 = -4(16)
A5 = -64

So the answer is B.

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3 years ago

Read 2 more answers

1) Lithium isotope rations are important to medicine, the 6Li/7Li ratio in a standard reference material was measured several ti

uysha [10]

Answer:

1) $0.0826052-2.776\frac{0.000013424}{\sqrt{5}}=0.082588$

$0.0826052+2.776\frac{0.000013424}{\sqrt{5}}=0.0826219$

b) $ME= 2.776\frac{0.000013424}{\sqrt{5}}=0.0000166653$

And we want 2/3 of the margin of error so then would be: $2/3 ME = 0.00001111$

The margin of error is given by this formula:

$ME=z_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

And on this case we have that ME =0.00001111016 and we are interested in order to find the value of n, if we solve n from equation (1) we got:

$n=(\frac{z_{\alpha/2} s}{ME})^2$ (2)

Replacing we got:

$n=(\frac{2.776(0.000013424)}{0.00001111})^2 =11.25 \approx 12$

So the answer for this case would be n=12 rounded up to the nearest integer

Step-by-step explanation:

Information given

0.082601, 0.082621, 0.082589, 0.082617, 0.082598

We can calculate the sample mean and deviation with the following formulas:

$\bar X= \frac{\sum_{i=1}^n X_i}{n}$

$s = \sqrt{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}}$

$\bar X=0.0826052$ represent the sample mean

$\mu$ population mean

s=0.000013424 represent the sample standard deviation

n=5 represent the sample size

Part 1

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

The degrees of freedom, given by:

$df=n-1=5-1=4$

The Confidence level is 0.95 or 95%, and the significance would be $\alpha=0.05$ and $\alpha/2 =0.025$ , the critical value would be using the t distribution with 4 degrees of freedom: $t_{\alpha/2}=2.776$

Now we have everything in order to replace into formula (1):

$0.0826052-2.776\frac{0.000013424}{\sqrt{5}}=0.082588$

$0.0826052+2.776\frac{0.000013424}{\sqrt{5}}=0.0826219$

Part 2

The original margin of error is given by:

$ME= 2.776\frac{0.000013424}{\sqrt{5}}=0.0000166653$

And we want 2/3 of the margin of error so then would be: $2/3 ME = 0.00001111$

The margin of error is given by this formula:

$ME=z_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

And on this case we have that ME =0.00001111016 and we are interested in order to find the value of n, if we solve n from equation (1) we got:

$n=(\frac{z_{\alpha/2} s}{ME})^2$ (2)

Replacing we got:

$n=(\frac{2.776(0.000013424)}{0.00001111})^2 =11.25 \approx 12$

So the answer for this case would be n=12 rounded up to the nearest integer

3 0

3 years ago