Originally Posted by

**rowdy3** 1. Max bought 5 notebooks and 4 pens. He spent a total of $10.65. Emily bought 3 notebooks and 3 pens for a total of $7.50. How much did the notebook and pens cost each.

2. Mr. Smith inherits $45,000. He invests part of the money into mutal funds giving him 4% return, and he invests the other part at the stock markets giving him 6%. At the end of the year he earned $2430 of interest. How much did he invest in both accounts?

1. This is what I did.=====>your first part is ok

-3(5n+4p=10.65)

4(3n+3p=7.50)

-15n -12p= -31.95

12n +12p= 30.00

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-3n/3 = 1.95/3

n=.65 (The cost of one notebook)

Substitute n=.65 into 1st equation:

$\displaystyle 5n+4p=10.65$

$\displaystyle 5(.65)+4P=10.65$ *

$\displaystyle 3.25+4p=10.65$

$\displaystyle 4p=7.40$

$\displaystyle p=1.85$ (The cost of one pen)

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-15n -12(.65) -31.95===>this is where you went South. You substituted the value you found for n into p. See * above.

-15n - 7.80 - 31.95 I added 7.80 and divided by -15

N=1.61 P=.65

What did I do wrong?

I have no idea on # 2.