Explanation for Question 22 From the Math (Calc) Section on the 2019 October Sat
In question 22, we're told that three M plus two minus five is equal 2 to M plus two. And so here, 3 we're going to look for what is the value of M plus two. 4 And so there's a couple ways that we can solve this. 5 I would always start a problem like this, 6 where we're looking for M plus two by solving for M because that's what 7 we know. Right. We know how to solve for one variable. 8 And sometimes you get lucky and it's really easy to just isolate M plus 9 two on its own and solve for it. But it's looking like in this 10 case, you're going to want to solve for M and then simply add to 11 at the end, right? So let's set up the equation, 12 let's rewrite it and we can start by distributing 13 the three, right? Because if we think about PEM dos, 14 when you solve an equation, you want to start with the parentheses. 15 So that'll give me three M plus six minus five is equal to M 16 plus two. So now I can combine like terms with regards 17 to the plus six and the minus five and six minus five is one, 18 right? So I'll, I'll rewrite. This is three M plus one is equal to 19 M plus two. And so now I can just solve for M here, 20 right? I'll subtract one from both sides. 21 So I get all my normal numbers on the right side of the equation. 22 So three M these ones cancel, 23 and that gives me M plus one. And then I'll subtract this M from 24 both sides of the equation, so that all of my AMS are on the 25 left side. So I'm now separated. The M's from the normal numbers. 26 These will...