Question

8. Jim currently has $1,250 in his bank account

and Sally has $1,400 in her bank account.
Jim deposits $27.50 per week and Sally
deposits $20 per week into her account.
After how many weeks will they have the
same amount of money?l

Answer 1

Answer: 20 weeks

I forgot to make the rate of change negative but it is the same either way so ignore the explanation

Step-by-step explanation: You can represent the 2 bank accounts with equations, with y being the cost and x being the number of weeks.

Jim's equation is
`y=27.50x+1250`

Sally's equation is
`y=20x+1400`

Now you can solve by substitution for x. Since y= sally's equation and y= Jim's equation you can use the transitive property to say that Jim's equation = sally's equation.

`27.50x+1250=20x+1400`

Subtract 20x from both sides

`7.50x+1250=1400`

Subtract 1250 from both sides

`7.50x=150`

Divide both sides by 7.5

`x=20`

After 20 weeks they will have the same amount of money