math help plssss...?

Question

Can you help me solve this math problem?

A banker invested a portion of $10,000 at 5% interest per year and the remainder 4% interest per year. If the banker received $470 in interest after 1 year, how much was invested at each rate?

Answer 1

It would be set up like this:

(10,000-x).05 + .04x = 470
so, 500 - .05x + .04x = 470
500 - .01x = 470
500 - 470 = .01x
30 = .01x
3,000 = x
Therfore, 7,000 would be invested at 5%, and 3,000 would be invested at 4%

After one year: (7,000 x .05) + (3,000 x .04)=
350 + 120 = 470

Answer 2

call the portion invested at 5% x

x*5%+(10000-x)*4%=470
solve for x

This yields $7000 at %5 and $3000 at 4%

Check the answer
7000*5%+3000*4%=470??
Yes

Answer 3

The answer is $7000 at 5% = $350 in interest and $3000 at 4% = $120 in interest. I used a TI83 to get the answer and will tell you how if you wish.

Answer 4

He invested n dollars at 5%.
That means he invested 10,000 - n dollars at 4%.

0.05n + 0.04(10,000 - n) = 470
0.05n + 400 - 0.04 n = 470
0.01n = 70
n = 7000 $7000 at 5%
10,000 - 7000 = $3000 at 4%

Answer 5

If this a real question 2 is a subset of the real huge form line plus a subset of the real huge form line as a outcome the answer is a subset in the real huge form line on the effective area