It's a reflection across the y axis because They are both still equal(all sides are equal) but flipped around. Also, if you calculate, all the midpoints of corresponding points are on the y axis, which shows that it is a reflection over the y axis and nothing more.
It could also be reflect across the x axis, then the y axis, then the x axis again because the reflections across the x axis cancel out with each other. So it is basically is a reflection across the y axis.
Choice 4 because when you rotate it by 180 it lands in the third quadrant exactly one reflection away. When you reflect it across the x axis, it becomes the desired triangle.
Choices 1 and 2 and 4.
Second option:
-7x^2+4x+2
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 <em>t</em>.
We know half-life is 5730 years and that the parchment has retained 74% of its Carbon-14. For 
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. <em>h</em> 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.
Now, solve. First, divide by 100.
Take the log of everything
Divide the entire equation by log (0.5) and multiply the entire equation by 5730 to isolate the <em>t</em> and get
Use your calculator to solve that giant mess for <em>t </em>and you'll get that <em>t</em> 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.
The lengths of two sides is not enough information to determine a unique triangle. There are an infinite number of possible correct answers. If 'x' is the length of the third side, then its length can be anything between 3 and 13.
