00:01
So i'm going to abbreviate nickels as n and d.
00:03
And my goal in solving this is just to create a system of equations, two linear equations that i could use to solve.
00:09
Now, in my two linear equations, i'm going to talk about my total number of coins, and i'm also going to talk about my money value.
00:17
Okay, so first i know that i have $1 .65 in nickels and coins.
00:23
Now, whenever i'm talking about money, i have to do the monetary worth of nickels, right? and dimes.
00:28
So how much are nickels? five cents.
00:30
Which is equivalent in dollars to .05, so 0 .05n plus how much are dimes worth? 10 cents.
00:39
So as a decimal in dollar amount, 0 .10 times d.
00:43
So everything in this equation has dollars.
00:47
Then i also know bob has nine more nickels than dives.
00:52
Okay, nine more.
00:53
So i have nine more nickels than dimes.
00:58
Which one does he have more of? he has more nickels, so equals the number of nickels.
01:05
I'm going to add nine to the dimes because nickels will be greater, so i have to add to the dimes.
01:10
Okay, so now i have these two equations.
01:13
How am i going to solve this? well, i can solve by elimination, substitution, graphing...