You invested a total of $9,000 at 4 1/2 % and 5% simple interest. During one year, the two accounts earned $435. How much did you invest in each account

Respuesta :

Answer:

The amount invested at 4.5% was [tex]\$3,000[/tex]

The amount invested at 5% was [tex]\$6,000[/tex]

Step-by-step explanation:

we know that

The simple interest formula is equal to

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

where

I is the Final Interest Value

P is the Principal amount of money to be invested

r is the rate of interest  

t is Number of Time Periods

Let

x -----> the amount invested at 4.5%

9,000-x -----> the amount invested at 5%

in this problem we have

[tex]t=1\ year\\ P1=\$x\\ P2=\$(9,000-x)\\I=\$435\\r1=0.045\\r2=0.05[/tex]

substitute

[tex]435=x(0.045*1)+(9,000-x)(0.05*1)[/tex]

[tex]435=0.045x+450-0.05x[/tex]

[tex]0.05x-0.045x=450-435[/tex]

[tex]0.005x=15[/tex]

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

so

[tex]9,000-x=\$6,000[/tex]

therefore

The amount invested at 4.5% was [tex]\$3,000[/tex]

The amount invested at 5% was [tex]\$6,000[/tex]