# Ank pays 5% simple interest on money deposited

1. Jan 16, 2005

### Erin_Sharpe

I dont know where to begin with this question... could some give me a few pointers? I'd appreciate it.

Bank pays 5% simple interest on money deposited, the credit union pays 4% with an added bonus of 25$if the money stays in the account for a year: 1) if x represents the amt of$ deposited and y represents $earned in year, write equations to model the money earned as a function of the amount invested at the bank and at the credit union (using above information) 2) determine how much$ must be invested before an employee would earn more moeny with the bank than he would with the credit union.

3) IF the credit union incresed the bonus to \$30 how much money must be invested before an employee would earn more money with bank than he would with the credit union.

I'm not asking for the answers... I'm just asking for a point in the right direction, or just some explanation.

Thanks a bunch,
Erin

2. Jan 17, 2005

### HallsofIvy

Staff Emeritus
For the bank, y= 0.05x. For the credit union, y= 0.04x+ 25.

For what x is y= 0.05x= 0.04x+ 25?

Just replace the 25 with 30 are redo 1 and 2.

I'm not asking for the answers... I'm just asking for a point in the right direction, or just some explanation.

Thanks a bunch,
Erin [/QUOTE]