)is on the line y=2x+5 find the other coordinate

Think about this. What do the numbers in a coordinate stand for? They stand for X and Y. If you're trying to figure out what the X is, wouldn't you be solving for x? And didn't they just give you an equation? ;) First off, do you see how the "Y" value is given to you in the coordinate? All you have to do is substitute that 3 in for the "y" in the equation! 3=2x+5. Hey that looks like a simple equation! First, you need to subtract 5 from the other side of the equation. Now you're left with 2x=-2. Divide both sides by 2, and you get that x=-1. Now, just substitute that "x' value into the coordinate, and your answer should come out to be (-1, 3). :D