Kyra had $20,000 to invest. She decided to put the money into three different aCounts earning 3%, 5%, and 7%simple interest respectively, and she earned a total of $920.00 in interest. She invested half as much money at 7%as at 3%. How much did she invest in each aCount?a. Write a system of equations that models this situation.b. Find the amount invested in each aCount

Answer:$8000, $4000 and $8000.Step-by-step explanation:Let the amount invested in 3%, 5% and 7% simple interest are a, b and c.Given that, she invested half as much money at 7% as at 3%.so, c=a/2, ⇒ a=2c. ...... (1)Now, a+b+c =20000 ........ (2), ⇒3c+b =20000 {From equation (1)}......... (3)She earned as interest a total of $920.Hence, 3a/100+5b/100+7c/100 =920⇒ 3a+5b+7c =92000⇒13c +5b =92000 {From equation (1)} ..... (4)Solving equations (4) and (3), we get 13a+5(20000-3c) =920002c = 8000⇒ c= 4000. then a= 2c =8000Again from equation (2), b=20000-4000-8000=8000Therefore, the amount invested in the three accounts are $8000, $4000 and $8000. (Answer)