Sunday

February 1, 2015

February 1, 2015

Posted by **jerson** on Tuesday, April 6, 2010 at 7:29pm.

0.08x+0.02y=310 Solve the system using the method of addition?=.

ok this is how my book says solve it

[2] x - y=100 -----> 2x-2y=2000

[-25] 0.08x+0.02y=310 -->-2x-0.5y=-7750

where and how did they get [-25]?

- math -
**Reiny**, Tuesday, April 6, 2010 at 7:42pmThey were trying to eliminate the decimals, but they did it in a very clumsy way

I would have multiplied the second by 100

8x + 2y = 31000

then the first by 2

2x - 2y = 2000

trivial from here on ...

leaving a decimal after you multiplied by something sort of defeats the purpose, why didn't they just multiply the first by 50 and leave the first alone.

That would have done the trick also.

**Answer this Question**

**Related Questions**

algebra - Money is invested at two rates of interest. One rate is 8% and the ...

algebra - A total of $12,000 is invested in two funds paying 9% and 11% simple ...

Math - Larry has an annual return of $213.00 from $3000.00 invested at simple ...

math - A student invests two sums of money at 3% and 4% interest, receiving a ...

algebra - James invested some money at 12% interest. James also invested $188 ...

math - Different Interest Rates. Mrs. Brighton invested $30,000 and received a ...

math - you invested $4000 in two accounts paying 2% and 9% annual interest, ...

Math - Help! Toshiro Hashimoto invested some money at 4.5% simple interest and $...

Math - Two investments are made totaling $4800. In the first year they yield a ...

algebra - Glenn invested some money is a certificate of deposit (CD) with an ...