Alvin has $760 less invested in 7% than he has at 5%. if his annual income from these two investments is $51.20, how much does he have invested at each rate?

Alvin invested $110 at rate of 7% and invested $870 at rate of 5%

Step-by-step explanation:

we know that

The simple interest formula is equal to

where

I is the Interest Value

P is the Principal amount of money to be invested

r is the rate of interest  

t is Number of Time Periods

in this problem

Let

x------> the amount of money invested at rate of 5%

At rate of 7%

we have

At rate of 5%

we have

substitute in the formula

therefore

Alvin invested ($870-$760)=$110 at rate of 7%

Alvin invested $870 at rate of 5%