4. helene invested a total of $1000 in two simple-interest bank accounts. one account paid 5% annual interest; the other paid 6% annual interest. the total amount of interest she earned after 1 year was $58. find the amount invested in each account

Let $x be the amount of money Helene invested in first account. Then $(1000-x) is the amount of money she invested in second account.

1. First account paid 5% annual interest. 5% from $x is $0.05x.

2. Second accoubt paid 6% annual interest. 6% from $(1000-x) is $0.06(1000-x).

3. The total amount of interest she earned after 1 year was $58. This means that

0.05x+0.06(1000-x)=58.

Solve this equation:

0.05x+0.06·1000-0.06x=58,

0.05x+60-0.06x=58,

-0.01x=58-60,

-0.01x=-2,

0.01x=2,

x=200.

1000-x=1000-200=800.

Helene invested $200 in 1st account and $800 in 2nd account.

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional