Help with 21 and not 22 please

I need to finish this usa test prep now plz help

Slav-nsk [51]

Answer:

R = 101

S = 131

Step-by-step explanation:

First, you will want to get your angle T. Since T is on the same line as the angle with 128 degree, you can easily find angel T. They are supplementary angels and form 180.

T=180-128

T=52

You also know that all angles in a triangle equal to 180

Use that to find angle S

180 = R+S+T

180 = 79 + S + 52

180 - 79 - 52 = S

49 = S, exterior S = 180-49 = 131

Exterior R = 180 - 79 = 101

Now add all your exteriors

8 0

2 years ago

Scientist can determine the age of ancient objects by a method called radiocarbon dating. The bombardment of the upper atmospher

Artemon [7]

Answer: 2500 years

Step-by-step explanation:

I'm not quite sure if I'm doing this right myself but I'll give it a shot.

We use this formula to find half-life but we can just plug in the numbers we know to find t.

$A(t)=A_{0}(1/2)^t^/^h$

We know half-life is 5730 years and that the parchment has retained 74% of its Carbon-14. For $A_{0$ let's just assume that there are 100 original atoms of Carbon-14 and for A(t) let's assume there are 74 Carbon-14 atoms AFTER the amount of time has passed. That way, 74% of the C-14 still remains as 74/100 is 74%. Not quite sure how to explain it but I hope you get it. h is the last variable we need to know and it's just the half-life, which has been given to us already, 5730 years, so now we have this.

$74=100(1/2)^t^/^5^7^3^0$

Now, solve. First, divide by 100.

$0.74=(0.5)^t^/^5^7^3^0$

Take the log of everything

$log(0.74)=\frac{t}{5730} log(0.5)$

Divide the entire equation by log (0.5) and multiply the entire equation by 5730 to isolate the t and get

$5730\frac{log(0.74)}{log(0.5)} =t$

Use your calculator to solve that giant mess for t and you'll get that t is roughly 2489.128182 years. Round that to the nearest hundred years, and you'll find the hopefully correct answer is 2500 years.

Really hope that all the equations that I wrote came out good and that that's right, this is definitely the longest answer I've ever written.

5 0

2 years ago

Diego lives 1/2 mile from school. Jonah lives 5% as far from school as Diego. How far, in miles, does diego live from school?

Elden [556K]

Answer:

The answer is .25

Step-by-step explanation:

convert 1/2 to .5 the multiply .5 by .5 which gives you .25

hope this helps

7 0

2 years ago

Mr. Chang’s class has 28 students, 4/7 of whom are girls. Which equation shows how to determine the number of girls in Mr. Chang

mars1129 [50]

Answer:

b

Step-by-step explanation:

6 0

2 years ago

Read 2 more answers

∆PQR has vertices P(5, –2), Q(1, –4), and R(3,3).Reflect ∆PQR about the y-axis, translate 4 units down, and reflect about the x-

JulsSmile [24]

Answer:

P(-5,6) Q(-1,8) R(-3,1)

3 0

3 years ago