00:01
So in this problem, our end goal is to find out how old is ravi as well as nita now.
00:06
So because we don't know what their ages are, what we can do is we can call them a variable.
00:12
So i'm going to let r represent robbie's age now.
00:15
So robbie's age now.
00:18
And i'm going to let n represent nita's age now.
00:24
Okay.
00:24
So now let's start with the first piece of information.
00:27
So right now, ravi is six years older than nita.
00:31
So ravi, so that would be r, is represents equals.
00:35
So he's six years old than neither.
00:36
So that means we would take nita's age, which is n, and we would add six to this.
00:41
So again, this equation represents ravi's age now.
00:44
Now, we're told three years ago that ravi was twice as old as nita, but here's what you're going to be careful.
00:50
Ravi r is representing his age now.
00:53
So three years ago, he was three years younger, meaning that r minus three would represent ravi's age three years ago.
01:01
So we're going to start by using r minus 3.
01:05
So again, that represents robbie's age three years ago.
01:08
Well, at that time, he was twice as old as neither.
01:12
Well, twice means that we would multiply it by 2.
01:15
But be careful.
01:17
We're not just multiplying n by 2 because n is how old she is now.
01:21
We have to multiply her age three years ago by 2.
01:25
So to represent this, we're going to take 2.
01:28
And then we're going to want to multiply this by n minus 3.
01:31
3 because again n minus 3 would represent needs as age three years ago perfect so now we have this equation so we can go ahead and solve so to solve because in our first equation we have r is equal to n plus 6 what i'm going to do is substitute n plus 6 in for r in our second equation which means we're going to have n plus 6 i apologize my computer's being a little slow then we're going to bring down to minus 3 equals, well, why don't we go ahead and get rid of those parentheses by distributing? 2 times n is equal to 2n, and then we're going to have 2 times negative 3, which is negative 6...
