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March 30, 2015

March 30, 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.

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