Explanation for Question 18 From the Math (Calc) Section on the 2017 May Sat
Question 18 gives us a system of equation and we're asked to solve for 2 the Y coordinate of the solution. 3 Now make sure when you are at your final answer, 4 you're solving for the why not. The Xs are really easy to mistake to 5 make just double check at the end. First type of system of equations is 6 just solving one of the equations for one variable you can do either, 7 but I'm definitely going to go with the bottom one because it's a lot 8 easier to manipulate. So to solve for X here, 9 all we do is Ottawa to both sides and we're left with X equals 10 five. Plus Y. Now I'm going to switch just two X 11 equals Y plus five, just because that's what we're used to seeing the 12 variable in front of the number. And we're going to have to foil in 13 a few steps. So it's just like making it easier for the future. 14 Having it in this format. Next step of system of equations is 15 just plugging it into the other ver um, 16 to the other equation so that you're left with one equation, 17 with one variable, and then you can solve. 18 So if we plug in, whenever we see X, 19 we plug in Y plus five, we have Y plus five squared 20 plus Y equals seven. 21 Um, our next step then is to solve for Y so solve for the 22 variable to do that. We first have to foil, 23 make sure we do have a squared right here. We can distribute because there's 24 a plus sign between the two numbers. 25 So we have to foil. This looks like this. 26 So Y plus five squared just means that you have Y plus five twic...