Flash Flash Revolution - View Single Post - [High School- Algebra 2] System of Equations (Word Problems)

**Silvuh** · 11-9-2008, 06:24 PM

As mentioned, the percents weren't properly converted in to decimals. But, they shouldn't be in the first equation. If you borrow 6000 dollars and split it between rates, well. The equation should simply be a split: X + Y = 6000. No rates involved.

And your equation 3.5(X+Y) = 3150 is saying that the rates are both 100%. Or, I = Pt. (Also, if you divide out the 3.5, you get X+Y=900, which means that you only have 900 dollars to start out with, and that's not true.)
The formula for simple interest is I = Prt. This is where you put the rates in.
The second equation should be 3.5 ( 0.155X + 0.1425Y ) = 3150.

Basically, you put your rates in the wrong equation.

And you can solve it from here.

At least I think this is right...

11-9-2008, 06:24 PM	#6
Silvuh quit Join Date: Apr 2005 Location: anywhere but here Posts: 938	Re: [High School- Algebra 2] System of Equations (Word Problems) As mentioned, the percents weren't properly converted in to decimals. But, they shouldn't be in the first equation. If you borrow 6000 dollars and split it between rates, well. The equation should simply be a split: X + Y = 6000. No rates involved. And your equation 3.5(X+Y) = 3150 is saying that the rates are both 100%. Or, I = Pt. (Also, if you divide out the 3.5, you get X+Y=900, which means that you only have 900 dollars to start out with, and that's not true.) The formula for simple interest is I = Prt. This is where you put the rates in. The second equation should be 3.5 ( 0.155X + 0.1425Y ) = 3150. Basically, you put your rates in the wrong equation. And you can solve it from here. At least I think this is right... __________________ Last edited by Silvuh; 11-9-2008 at 06:27 PM..