Jessica opened a bank account that earns 2% interest compounded annually. Her initial deposit was 100 bucks, and she uses the expression 100 X to the tee to find the value of the account after two years 37 what is the value of x in the expression? What is the value? So they're basically asking not only for you to find out what x even stands for here, like what is it the variable for but they're also asking for some kind of value for it. Okay, well kind of really use the process of elimination. So what is this hundred here?

Well, that's just her initial deposit, right? Because she put in 100. What is t? t is the account after two years, it's just the amount of years the account has been open for. So then x has to be the other thing and the other thing is the interest the interest that as compound right because the amount that her initial deposit is going to earn her or The total amount that she's going to have, after some kind of years is going to be a combination between her initial amount, or her initial deposit, the interest and the amount of years or two years that the accounts been open. So the last guy, x has to be the interest.

So how do we find out the interest? How do we actually write that out? They tell us 2% it earns 2%. How do you write that as a value? Well, remember what we do when we're dealing with percentages. If we're earning, that means something is increasing.

So if I multiply something by one, that means it's not changing, right? If I multiply 10 by one, it's just 10. But if I multiply 10, by something less than one, let's say point five or point eight, that means I'm decreasing the value of 10. Now it's becoming five or now it's becoming eight. But if I multiply 10, or anything by a value that is greater than one now, that 10 or whatever that value is increasing. So when I'm told that the bank account earns her 2% that means her hundred dollars is increasing.

That means I'm going to multiply that hundred dollars by something more than one. Okay? Now how much more than one? Well, we're told 2%. How do you write 2%? Well, percent literally means per cent or per 100.

So to over 100 is equal to point O two. So that is literally 2% in decimal form, check out our initial videos on percentages if you guys are a little confused on this. So point oh two, so we add point O two to one. And we get 1.02. So 1.02 is the amount that you multiply $100 with to show that 2% increase. I mean, let's say so that is our value, by the way.

But let's say the bank earned her maybe 10%. How would you write that out? Well, that would be 100 times 1.1. What if there was a discount like maybe not the bank but maybe Went to a store and she got a discount on a laptop. Let's say it was 20%. How much would you multiply the original amount by to reflect that decrease or that discount?

Well, if you're decreasing 20%, if you're taking off 20% off of the initial amount, that is like multiplying by point eight, you subtract point two which is 20% from one and you get point A, and you multiply that by the original value. So just again, check out the videos on how to multiply values by the percentages to see how we get that. All right.