You invested $ 7000 between two accounts paying 3 % and 5 % annual? interest, respectively. If the total interest earned for the year was $ 290 comma how much was invested at each? rate?

Respuesta :

Answer:

In the first account was invested [tex]\$3,000[/tex]  at 3%

In the second account was invested [tex]\$4,000[/tex]  at 5%

Step-by-step explanation:

we know that

The simple interest formula is equal to

[tex]I=P(rt)[/tex]

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 we have

First account

[tex]t=1 years\\ P=\$x\\ r=0.03[/tex]

substitute in the formula above

[tex]I=x(0.03*1)[/tex]

[tex]I=0.03x[/tex]

Second account

[tex]t=1 years\\ P=\$(7,000-x)\\ r=0.05[/tex]

substitute in the formula above

[tex]I=(7,000-x)(0.05*1)[/tex]

[tex]I=350-0.05x[/tex]

Remember that

The interest is equal to [tex]\$290[/tex]

so

Adds the interest of both accounts

[tex]0.03x+350-0.05x=\$290[/tex]

[tex]0.05x-0.03x=350-290[/tex]

[tex]0.02x=60[/tex]

[tex]x=\$3,000[/tex]

therefore

In the first account was invested [tex]\$3,000[/tex]  at 3%

In the second account was invested [tex]\$7,000-\$3,000=\$4,000[/tex]  at 5%