Thursday

March 26, 2015

March 26, 2015

Posted by **Joe** on Sunday, March 8, 2009 at 2:09pm.

- investment question -
**drwls**, Sunday, March 8, 2009 at 3:47pmLet their investments be L (Laura) and S (Scott). Laura's annual interest rate is I (expressed as a decimal) and Scott's is I + 0.02

S = L + 3000

800 = S*(I + 0.02)

400 = L I

You have three equations in three unknowns, which is enough to solve for all of them.

800 =(L+300)(I+0.02)

800 = LI + 300I +0.02L + 6

= 400 + 300I + 0.02L+ 6

= 400 + 300*400/L + 0.02L + 6

= 406 + 120000/L +0.02L

This can be turned into a quadratic equation for L. Take the positive root.

- investment question -
**Anonymous**, Thursday, February 2, 2012 at 10:09pmActually, you should take the negative root. You should plug both answers into the original equation to see which one fits. The one that makes sense (i.e. 800=800) should be the correct one.

Don't forget that Scott invested 3,000 more than Sally (S = L + 3000). You just solved for L. The question is asking for what S is. You're not done yet.

**Answer this Question**

**Related Questions**

college algebra - Scott and Laura have both invested some money. Scott invested...

algebra - Sylvia Acuff invested money received from an inheritance for 9 months ...

College alerbra - Scott invested a total of $9500 at two separate banks. One ...

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

Math - An investment advisor invested a total of $12,000, part at 2.5% annual ...

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

math - Mrs. Brighton invested $30,000 and received a total of $2,300 in interest...

Math - melissa invested a some of money at 3% annual simple inter she invested ...

Algebra - I invested $42,000 in three funds paying 5%, 7%, and 9% simple ...

math - An investment adviser invested $14,000 in two accounts. One investment ...