What do "C(3, 5)" and "r= 7" mean?

Does this have anything to do with the original question in this thread?

I hope someone helps me with these questions

C(3,5) e r =7

C(0,0) e r =9

C(-2,-1) e r=5

Your English is excellent! Much better than my (insert pretty much any language here).

I would change the word order slightly: "Write the (equations for) the lines that are parallel and perpendicular to the line y= 2x+ 3 that pass through (1, 1)".

The slope of y= 2x+ 3 is 2. A line parallel to that also has slope 2 so has equation y= 2x+ b for some number b. What must b equal in order that this line pass through (1, 1)? A line perpendicular to that has slope -1/2 so equation y= (-1/2)x+ b for some number b. What must b equal in order that this line pass through (1, 1)?

Hey, not sure how to translate this from my native language, I hope you understand what I mean.

Write down for the line
y = 2x + 3 perpendicular and parallel lines passing through the point
(1; 1) equations.