Need help with these

What is the solution of x=2+ square root x-2?

alex41 [277]

So I'm going to assume that this question is asking for non extraneous solutions, or solutions that are found in the equation and are valid solutions when plugged back into the equation. So firstly, subtract 2 on both sides of the equation:

$x-2=\sqrt{x-2}$

Next, square both sides:

$(x-2)^2=x-2\\(x-2)(x-2)=x-2\\x^2-4x+4=x-2$

Next, subtract x and add 2 to both sides of the equation:

$x^2-5x+6=0$

Now we are going to be factoring by grouping to find the solution(s). Firstly, what two terms have a product of 6x^2 and a sum of -5x? That would be -3x and -2x. Replace -5x with -2x - 3x:

$x^2-2x-3x+6=0$

Next, factor x^2 - 2x and -3x + 6 separately. Make sure that they have the same quantity on the inside of the parentheses:

$x(x-2)-3(x-2)=0$

Now you can rewrite the equation as $(x-3)(x-2)=0$

Now, apply the Zero Product Property and solve for x as such:

$x-3=0\\x=3\\\\x-2=0\\x=2$

Now, it may appear that the answer is C, however we need to plug the numbers back into the original equation to see if they are true as such:

$2=2+\sqrt{2-2}\\2=2+\sqrt{0}\\2=2+0\\2=2\ \textsf{true}\\\\3=2+\sqrt{3-2}\\3=2+\sqrt{1}\\3=2+1\\3=3\ \textsf{true}$

Since both solutions hold true when x = 2 and x = 3, your answer is C. x = 2 or x = 3.

8 0

3 years ago

Matt invests $1,669 in a saving account with a fixed annual interest rate of 2% compounded 12 times per year. How long will it t

vesna_86 [32]

Answer:

It will take 4.84 years

Step-by-step explanation:

The initial amount that Matt invested was $1669. It means that principal is

P = 1669

It was compounded 12 times per year. So

n = 12

The rate at which the principal was compounded is 2%. So

r = 2/100 = 0.02

The formula for compound interest is

A = P(1+r/n)^nt

A = total amount in the account at the end of t years.

A = 1,844.38

Therefore

1,844.38 = 1669(1+0.02/12)^(12×t)

1,844.38/1669 = (1.0017)^(12t)

1.1051 = (1.0017)^(12t)

Taking log to base 10 of both sides, it becomes

Log 1.1051 = log 1.0017^(12t)

Log 1.1051 = 12tlog 1.0017

0.043 = 0.00074 × 12t

0.043 = 0.00888t

t = 0.043/0.00888

t = 4.84 years

6 0

3 years ago

Diana earns $9.95 per hour

Sav [38]

Answer:

m = $9.00 * h.

Step-by-step explanation:

hours: 4, 5, 6, 7,

money: 34, 42.5, 51, 59.5,

5 0

3 years ago

What is equivalent to 4(b+5)

topjm [15]

4b+20 because you disrepute the 4

6 0

2 years ago

Use synthetic division and remainder theorem p(x) = 3x^3 - 5x^2 - x + 2. p(-1/3)=

Alik [6]

Answer:

5/3

Step-by-step explanation:

-1/3 goes on the outside and since we have our polynomial in standard form with no in between terms missing, 3,-5,-1,2 go inside because they are the coefficients of our polynomial.

-1/3 | 3 -5 -1 2

|

-------------------------------------

First step bring the 3 down inside. (3+0=3)

-1/3 | 3 -5 -1 2

|

-------------------------------------

3

Whatever goes below the bar, must be multiplied by outside number and put directly below next number inside.

-1/3 | 3 -5 -1 2

| -1

-------------------------------------

3

The numbers lined up vertically are added to get the numbers underneath the bar.

-1/3 | 3 -5 -1 2

| -1

-------------------------------------

3 -6

Again any number below the bar gets multiply to the number outside.

-1/3 | 3 -5 -1 2

| -1 2

-------------------------------------

3 -6

Again the numbers lined up vertically above the bar get added to get the number that goes underneath the bar there.

-1/3 | 3 -5 -1 2

| -1 2

-------------------------------------

3 -6 1

Multiply to outside number 1(-1/3)=-1/3.

This goes under the 2 inside.

-1/3 | 3 -5 -1 2

| -1 2 -1/3

-------------------------------------

3 -6 1

The last number we are fixing to be put is the remainder of (3x^3-5x^2-x+2)/(x+1/3) or you could say it is the value of p(-1/3) since:

P(x)/(x-c)=Q(x)+R/(x-c)

Multiply both sides by (x-c):

P(x)=Q(x)(x-c)+R

If you evaluate P at x=c, we get R:

P(c)=Q(c)(c-c)+R

P(c)=Q(c)*0+R

P(c)=R.

Let's finish:

-1/3 | 3 -5 -1 2

| -1 2 -1/3

-------------------------------------

3 -6 1 5/3

This means p(-1/3)=5/3.

We could have also got this by directly plugging in (-1/3) for x into 3x^3-5x^2-x+2.

7 0

3 years ago