Helene invested a total of $1,250 in two simple-interest bank accounts. One account paid 4% annual interest; the other paid 7% annual interest. The total amount of interest she earned after 1 year was $71.
Find the amount invested in each account.

$550 was invested in the 4% account while $700 was invested in the 7% account

Step-by-step explanation:

Let the amount invested in each account be $x and $y respectively

The sum of these two is $1,250

Mathematically;

x + y = 1250 •••••(i)

Now, let’s work with the interest rate;

4% of x + 7% of y = 71

4x/100 + 7y/100 = 71

Multiply through by 100

4x + 7y = 7100 •••••(ii)

From i;

x = 1250-y

Substitute this into ii

4(1250-y) + 7y = 7100

5000 - 4y + 7y = 7100

3y = 7100-5000

3y = 2100

y = 2100/3

y = 700

Recall;

x + y = 1250

700 + x = 1250

x = 1250 - 700

x = 550