The <span>Pythagorean Theorem tells us that

where c is the </span><span>hypotenuse and a and b are the other two sides. To solve for one of the shorter sides we need to rearrange:

We can then substitute known values, and solve:
</span>



recall your d = rt, distance = rate * time.
let's say we have two trains, A and B, A is going at 85 mph and B at 65 mph.
they are 210 miles apart and moving toward each other, at some point they will meet, when that happens, the faster train A has covered say d miles, and the slower B has covered then the slack from 210 and d, namely 210 - d.
When both trains meet, A has covered more miles than B because A is faster, however the time both have been moving, is the same, say t hours.
![\bf \begin{array}{lcccl} &\stackrel{miles}{distance}&\stackrel{mph}{rate}&\stackrel{hours}{time}\\ \cline{2-4}&\\ \textit{Train A}&d&85&t\\ \textit{Train B}&210-d&65&t \end{array}\\\\ \dotfill\\\\ \begin{cases} \boxed{d}=85t\\ 210-d=65t\\[-0.5em] \hrulefill\\ 210-\boxed{85t}=65t \end{cases} \\\\\\ 210=150t\implies \cfrac{210}{150}=t\implies \cfrac{7}{5}=t\implies \stackrel{\textit{one hour and 24 minutes}}{1\frac{2}{5}=t}](https://tex.z-dn.net/?f=%20%5Cbf%20%5Cbegin%7Barray%7D%7Blcccl%7D%20%26%5Cstackrel%7Bmiles%7D%7Bdistance%7D%26%5Cstackrel%7Bmph%7D%7Brate%7D%26%5Cstackrel%7Bhours%7D%7Btime%7D%5C%5C%20%5Ccline%7B2-4%7D%26%5C%5C%20%5Ctextit%7BTrain%20A%7D%26d%2685%26t%5C%5C%20%5Ctextit%7BTrain%20B%7D%26210-d%2665%26t%20%5Cend%7Barray%7D%5C%5C%5C%5C%20%5Cdotfill%5C%5C%5C%5C%20%5Cbegin%7Bcases%7D%20%5Cboxed%7Bd%7D%3D85t%5C%5C%20210-d%3D65t%5C%5C%5B-0.5em%5D%20%5Chrulefill%5C%5C%20210-%5Cboxed%7B85t%7D%3D65t%20%5Cend%7Bcases%7D%20%5C%5C%5C%5C%5C%5C%20210%3D150t%5Cimplies%20%5Ccfrac%7B210%7D%7B150%7D%3Dt%5Cimplies%20%5Ccfrac%7B7%7D%7B5%7D%3Dt%5Cimplies%20%5Cstackrel%7B%5Ctextit%7Bone%20hour%20and%2024%20minutes%7D%7D%7B1%5Cfrac%7B2%7D%7B5%7D%3Dt%7D%20)
You might want to stick to at most five questions at once, makes it easier for the rest of us. :)
17. T has a vertical line of symmetry (along the center line).
18. Z looks the same if you turn it halfway around.
19. The passes total to 150°, which is a little less than 180°, so I estimate it would be in front of Kai.
20. Left is the -x direction. Up is the +y direction. this is (x-6, y+4)
21. Every dilation has a center (where it's dilated from) and a scale factor (how much it's dilated).
22. It must be A, because it's the only one where the number of moves adds up to 16.
23. It can be determined to be B just by tracking where point C would end up through the transformation.
24. A 180° rotation flips the signs on both components to give you (-1, 6).
25. Right is the +x direction. Down is the -y direction. (x+3, y-5)
26. This is a reflection.
Need clarification on anything?
Start by y-k=m(x-h)
m= 3
k=2
h=1
so y-2=3(x-1)
distribute
y=3x-3+2
final answer: y=3x-1