Question

You can use addition and subtraction to investigate the daily fluctuations of a stock market balance.

The table shows the changes in value of Julio’s two stock market accounts.

Day
Account A

Value Change ($)

Account B

Value Change ($)

Monday 15 −5
Tuesday −11 12
Wednesday −25 −17
Thursday −14 −13
Friday 20 17
Julio had $100 in Account A on Sunday. How much money does he have in the account on Friday?

Enter the correct answer in the box.

Answer 1

$sunday \: 15 - 5$

Answer 2

given a table showing value changes in Julio's two market accounts , find balance in account A on friday

Explanation:

1. let the current balance in account A be denoted by 'x' ,previous balance in account B be denoted by 'y' and value change in account A be denoted by 'v'. Then we have,         $x=y+v$                                                                                      
2. starting from Sunday Julio's account A has balance  $$100$ let it be denoted as,      $x=100$  
3. next comes Monday  we have , $y=100\ \ \ \ and\ \ \ \ v=15$                                           then we get,  $x=100+15=115$  
4. next comes Tuesday we have, $y=115\ \ \ \ and\ \ \ \ v=-11$                                                then we get,  $x=115-11=104$  
5. next comes Wednesday we have, $y=104\ \ \ \ and\ \ \ \ v=-25$                                      then we get,  $x=104-25=79$    
6. next comes Thursday we have, $y=79\ \ \ \ and\ \ \ \ v=-14$                                     then we get, $x=79-14=65$  
7. next comes Friday we have, $y=65\ \ \ \ and\ \ \ \ v=20$                                             then we get, $x=65+20=85$    
8. On Friday, before value change the account has $$65$ and after value change has $$85$.