Gase

1. The radioisotope Iodine-123 is used in thyroid therapy. The half-life of this isotope is 13.27 hours.

Mandarinka [93]

1. Answer: D. <span>A = 100 (1/2)^t/13.27

</span>Exponent equation formula would be an= a0( 1+r)^t
In this question, the radio isotopes will become half of its weight after the half-life. So, the ratio would be -0.5 (r= -0.5)
The halftime is 13.27 hours, so the time will be divided by that number. The result would look like this:
an= a0( 1+r)^t
an= a0( 1-0.5)^t/13.27
an= a0( 1/2)^t/13.27

2. Answer: x= 74°

<span>The ladder and the building will make a right triangle with the ladder as the hypotenuse.
The foot of the ladder is 2 feet from the building, so the adjacent side is 2ft.
It reaches a point 7 feet high on the building, so the opposite side is 7ft</span>
You can find the angle by using the tan equation

tan x= opposite / adjacent
tan x= 7/2= 3.5
x= 74°

7 0

4 years ago

Create a matrix for this system of linear equations, The determinant of the coefficient matrix is

marin [14]

Answer: The determinant of the coefficient matrix is -15 and x = 3, y = 4, z = 1.

Step-by-step explanation: The given system of linear equations is :

$2x+y+3z=13~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(i)\\\\x+2y=11~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(ii)\\\\3x+z=10~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(iii)$

We are given to find the determinant of the coefficient matrix and to find the values of x, y and z.

The determinant of the co-efficient matrix is given by

$D=\begin{vmatrix}2 & 1 & 3\\ 1 & 2 & 0\\ 3 & 0 & 1\end{vmatrix}=2(2-0)+1(0-1)+3(0-6)=4-1-18=-15.$

Now, from equations (ii) and (iii), we have

$x+2y=11~~~~~\Rightarrow y=\dfrac{11-x}{2}~~~~~~~~~~~~~~~~~~~~~~~~~~(iv)\\\\\\3x+z=10~~~~~~\Rightarrow z=10-3x~~~~~~~~~~~~~~~~~~~~~~~~~(v)$

Substituting the value of y and z from equations (iv) and (v) in equation (i), we get

$2x+y+3z=13\\\\\Rightarrow 2x+\dfrac{11-x}{2}+3(10-3x)=13\\\\\Rightarrow 4x+11-x+60-18x=26\\\\\Rightarrow -15x+71=26\\\\\Rightarrow -15x=26-71\\\\\Rightarrow -15x=-45\\\\\Rightarrow x=3.$

From equations (iv) and (v), we get

$y=\dfrac{11-3}{2}=4,\\\\z=10-3\times3=1.$

Thus, the determinant of the coefficient matrix is -15 and x = 3, y = 4, z = 1.

3 0

3 years ago

<img src="https://tex.z-dn.net/?f=%5Csqrt%3F%20191" id="TexFormula1" title="\sqrt? 191" alt="\sqrt? 191" align="absmiddle" class

OlgaM077 [116]

13.8203 i think if i’m wrong i’m so sorry

5 0

3 years ago

Number 4 Pleases help need now

levacccp [35]

I believe the answer is 23 :)

3 0

4 years ago

PLEASE HELP I WILL GIVE BAINY LIST TO WHOEVER ANSWERS ALL THE QUESTIONS !!!!!

sergejj [24]

Answer:

1. $97\frac{3}{4}$

2. $3$ x $6\frac{3}{4}$ = $20\frac{1}{4}$

3. $77$ $\frac{1}{2}$

4. Yes (explanation given below)

Step-by-step explanation:

1. Find the area of the wall including the door...

Just multiply the numbers for the width and length.

$11\frac{1}{2}$ x $8\frac{1}{2}$ = $97\frac{3}{4}$

And now, as you can see.

$97\frac{3}{4}$ is our answer for 1.

2. Find the area of the door. (improper fraction)

Again, we just have to multiply, then simplify, and remember to keep it in improper fraction format.

$3$ x $6\frac{3}{4}$ = $20\frac{1}{4}$

so now, we can see that that is the area of the door, but according to the question, we have to leave the answer in the improper fraction format. To turn a mixed number into a improper fraction, we have to multiply the denominator of the fraction with the whole then, add the numerator, the answer that we get is going to be the numerator of the improper fraction and the denominator remains the same.

20 1/4 = 81/4 (improper fraction)

So, 81/4 is our answer for 2.

3. Without door space, give how much wall area there is. (mixed number)

So, as we already know that the door covers up 20 $\frac{1}{4}$ , so all what we have to do is, take the area of the Whole wall and door and subtract it by the door area.

WHOLE wall = 97 $\frac{3}{4}$

Door only = 20 $\frac{1}{4}$

$97\frac{3}{4}-20\frac{1}{4} = 77\frac{1}{2}$

So, hence, the answer for 3. is 77 $\frac{1}{2}$

4. Does Amelia have enough paint? Explain...

Yes, amelia has enough paint for covering the whole intire wall because she has enough paint for a 100 square feet, and the actual surfact area of her wall is JUST 97 3/4 square feet. So, she definitely has enough paint to cover that wall and door.

Thank You! Please mark me brainliest so that I get encouraged to make more great answers like this one!

5 0

2 years ago

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