Respuesta :

Answer:

y=10000 at rate 0.12 or 12%

x=8500 at rate 0.14 0r 14 %

Step-by-step explanation:

x+y=18500   ⇒ x=18500-y

0.14x+0.12y=2390 ( solve by substitution)

0.14(18500-y)+0.12y=2390

2590-0.14y+0.12y=2390

-0.02y=2390-2590

-0.02y=-200

y=-200/0.02

y=10000 at rate 0.12

x=18500-y

x=18500-10000=8500

x=8500 at rate 0.14

check : 0.14(8500)+0.12(10000)=2390 ( correct)

mathmate

Answer:

Amount invested at 14% = 8500

Amount invested at 12% =  10000

Step-by-step explanation:

Assume money was invested for one year.

18500 at 14% = 18500*0.14 = 2590

18500 at 12% = 18500*0.12 = 2220

actual interest earned = 2390

Let

x = ratio of money invested at 14%

1-x = ratio of money invested at 12%

Then

18500*x * 0.14 + 18500 * (1-x)*0.12 = 2390

0.14x - 0.12x = 2390/18500-0.12

0.02x = 0.1291892-0.12 = 0.0091892

x = 0.0091892/0.02 = 0.4594595

Amount invested in 14% = 18500 * x = 8500

Amount invested in 12% = 18500 * (1-x) = 10000

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