The missing justification in the proof is
<span>B) Substitution property of equality
The expression for sin</span>² x and cos² x is substituted to the other side of the equation. Since sin x = a/c, then sin² x = a²/c². Similarly, since cos x = b/c, then cos² x = b²/c². Adding to two results to the third statement.
Check the picture below, so the park looks more or less like so, with the paths in red, so let's find those midpoints.
![~~~~~~~~~~~~\textit{middle point of 2 points } \\\\ J(\stackrel{x_1}{-3}~,~\stackrel{y_1}{1})\qquad K(\stackrel{x_2}{1}~,~\stackrel{y_2}{3}) \qquad \left(\cfrac{ x_2 + x_1}{2}~~~ ,~~~ \cfrac{ y_2 + y_1}{2} \right) \\\\\\ \left(\cfrac{ 1 -3}{2}~~~ ,~~~ \cfrac{ 3 +1}{2} \right) \implies \left(\cfrac{ -2 }{2}~~~ ,~~~ \cfrac{ 4 }{2} \right)\implies JK=(-1~~,~~2) \\\\[-0.35em] ~\dotfill](https://tex.z-dn.net/?f=~~~~~~~~~~~~%5Ctextit%7Bmiddle%20point%20of%202%20points%20%7D%20%5C%5C%5C%5C%20J%28%5Cstackrel%7Bx_1%7D%7B-3%7D~%2C~%5Cstackrel%7By_1%7D%7B1%7D%29%5Cqquad%20K%28%5Cstackrel%7Bx_2%7D%7B1%7D~%2C~%5Cstackrel%7By_2%7D%7B3%7D%29%20%5Cqquad%20%5Cleft%28%5Ccfrac%7B%20x_2%20%2B%20x_1%7D%7B2%7D~~~%20%2C~~~%20%5Ccfrac%7B%20y_2%20%2B%20y_1%7D%7B2%7D%20%5Cright%29%20%5C%5C%5C%5C%5C%5C%20%5Cleft%28%5Ccfrac%7B%201%20-3%7D%7B2%7D~~~%20%2C~~~%20%5Ccfrac%7B%203%20%2B1%7D%7B2%7D%20%5Cright%29%20%5Cimplies%20%5Cleft%28%5Ccfrac%7B%20-2%20%7D%7B2%7D~~~%20%2C~~~%20%5Ccfrac%7B%204%20%7D%7B2%7D%20%5Cright%29%5Cimplies%20JK%3D%28-1~~%2C~~2%29%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill)
![~~~~~~~~~~~~\textit{middle point of 2 points } \\\\ L(\stackrel{x_1}{5}~,~\stackrel{y_1}{-1})\qquad M(\stackrel{x_2}{-1}~,~\stackrel{y_2}{-3}) \qquad \left(\cfrac{ x_2 + x_1}{2}~~~ ,~~~ \cfrac{ y_2 + y_1}{2} \right) \\\\\\ \left(\cfrac{ -1 +5}{2}~~~ ,~~~ \cfrac{ -3 -1}{2} \right) \implies \left(\cfrac{ 4 }{2}~~~ ,~~~ \cfrac{ -4 }{2} \right)\implies LM=(2~~,~~-2) \\\\[-0.35em] ~\dotfill](https://tex.z-dn.net/?f=~~~~~~~~~~~~%5Ctextit%7Bmiddle%20point%20of%202%20points%20%7D%20%5C%5C%5C%5C%20L%28%5Cstackrel%7Bx_1%7D%7B5%7D~%2C~%5Cstackrel%7By_1%7D%7B-1%7D%29%5Cqquad%20M%28%5Cstackrel%7Bx_2%7D%7B-1%7D~%2C~%5Cstackrel%7By_2%7D%7B-3%7D%29%20%5Cqquad%20%5Cleft%28%5Ccfrac%7B%20x_2%20%2B%20x_1%7D%7B2%7D~~~%20%2C~~~%20%5Ccfrac%7B%20y_2%20%2B%20y_1%7D%7B2%7D%20%5Cright%29%20%5C%5C%5C%5C%5C%5C%20%5Cleft%28%5Ccfrac%7B%20-1%20%2B5%7D%7B2%7D~~~%20%2C~~~%20%5Ccfrac%7B%20-3%20-1%7D%7B2%7D%20%5Cright%29%20%5Cimplies%20%5Cleft%28%5Ccfrac%7B%204%20%7D%7B2%7D~~~%20%2C~~~%20%5Ccfrac%7B%20-4%20%7D%7B2%7D%20%5Cright%29%5Cimplies%20LM%3D%282~~%2C~~-2%29%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill)

now, let's check the other path, JM and KL
![~~~~~~~~~~~~\textit{middle point of 2 points } \\\\ J(\stackrel{x_1}{-3}~,~\stackrel{y_1}{1})\qquad M(\stackrel{x_2}{-1}~,~\stackrel{y_2}{-3}) \qquad \left(\cfrac{ x_2 + x_1}{2}~~~ ,~~~ \cfrac{ y_2 + y_1}{2} \right) \\\\\\ \left(\cfrac{ -1 -3}{2}~~~ ,~~~ \cfrac{ -3 +1}{2} \right) \implies \left(\cfrac{ -4 }{2}~~~ ,~~~ \cfrac{ -2 }{2} \right)\implies JM=(-2~~,~~-1) \\\\[-0.35em] ~\dotfill](https://tex.z-dn.net/?f=~~~~~~~~~~~~%5Ctextit%7Bmiddle%20point%20of%202%20points%20%7D%20%5C%5C%5C%5C%20J%28%5Cstackrel%7Bx_1%7D%7B-3%7D~%2C~%5Cstackrel%7By_1%7D%7B1%7D%29%5Cqquad%20M%28%5Cstackrel%7Bx_2%7D%7B-1%7D~%2C~%5Cstackrel%7By_2%7D%7B-3%7D%29%20%5Cqquad%20%5Cleft%28%5Ccfrac%7B%20x_2%20%2B%20x_1%7D%7B2%7D~~~%20%2C~~~%20%5Ccfrac%7B%20y_2%20%2B%20y_1%7D%7B2%7D%20%5Cright%29%20%5C%5C%5C%5C%5C%5C%20%5Cleft%28%5Ccfrac%7B%20-1%20-3%7D%7B2%7D~~~%20%2C~~~%20%5Ccfrac%7B%20-3%20%2B1%7D%7B2%7D%20%5Cright%29%20%5Cimplies%20%5Cleft%28%5Ccfrac%7B%20-4%20%7D%7B2%7D~~~%20%2C~~~%20%5Ccfrac%7B%20-2%20%7D%7B2%7D%20%5Cright%29%5Cimplies%20JM%3D%28-2~~%2C~~-1%29%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill)
![~~~~~~~~~~~~\textit{middle point of 2 points } \\\\ K(\stackrel{x_1}{1}~,~\stackrel{y_1}{3})\qquad L(\stackrel{x_2}{5}~,~\stackrel{y_2}{-1}) \qquad \left(\cfrac{ x_2 + x_1}{2}~~~ ,~~~ \cfrac{ y_2 + y_1}{2} \right) \\\\\\ \left(\cfrac{ 5 +1}{2}~~~ ,~~~ \cfrac{ -1 +3}{2} \right) \implies \left(\cfrac{ 6 }{2}~~~ ,~~~ \cfrac{ 2 }{2} \right)\implies KL=(3~~,~~1) \\\\[-0.35em] ~\dotfill](https://tex.z-dn.net/?f=~~~~~~~~~~~~%5Ctextit%7Bmiddle%20point%20of%202%20points%20%7D%20%5C%5C%5C%5C%20K%28%5Cstackrel%7Bx_1%7D%7B1%7D~%2C~%5Cstackrel%7By_1%7D%7B3%7D%29%5Cqquad%20L%28%5Cstackrel%7Bx_2%7D%7B5%7D~%2C~%5Cstackrel%7By_2%7D%7B-1%7D%29%20%5Cqquad%20%5Cleft%28%5Ccfrac%7B%20x_2%20%2B%20x_1%7D%7B2%7D~~~%20%2C~~~%20%5Ccfrac%7B%20y_2%20%2B%20y_1%7D%7B2%7D%20%5Cright%29%20%5C%5C%5C%5C%5C%5C%20%5Cleft%28%5Ccfrac%7B%205%20%2B1%7D%7B2%7D~~~%20%2C~~~%20%5Ccfrac%7B%20-1%20%2B3%7D%7B2%7D%20%5Cright%29%20%5Cimplies%20%5Cleft%28%5Ccfrac%7B%206%20%7D%7B2%7D~~~%20%2C~~~%20%5Ccfrac%7B%202%20%7D%7B2%7D%20%5Cright%29%5Cimplies%20KL%3D%283~~%2C~~1%29%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill)

so the red path will be 
Answer: (1,7) (2,9) (3,11) (4,13)
Step-by-step explanation:
The function is y = 2x + 5. To find the y coordinates we will insert the values 1, 2, 3, and 4 for x.
y = 2(1) + 5
y = 7
So the first coordinate would be (1,7)
y = 2(2) + 5
y = 9
Second coordinate will be (2,9)
y = 2(3) + 5
y = 11
Third coordinate will be (3,11)
y = 2(4) + 5
y = 13
Fourth and final coordinate will be (4,13)
If x=mx-3 (which is not clear from your input),
3
then x-mx = -3, or mx-1x = 3, and x(m-1) = 3, and so x = ---------
m-1
Steps
find the Least Common Multiple of the denominators (which is called the Least Common Denominator).
Change each fraction (using equivalent fractions) to make their denominators the same as the least common denominator.
Then add (or subtract) the fractions, as we wish!
your denominators stay the same so its 20