Answer: J = 5w + 5
B = 4w + 12
They will have the same amount in week 7.
Step-by-step explanation: Look at the difference from one week to the next: for Jocelyn it's 5 per week, for Ben it's 4 per week
That's where the 5w and 4w come from.
Then look at the starting amounts in week 0: for J it's 5, for B it's 12.
Whatever they have in any future week (if no withdrawals or interest are made) is the starting amount + the amount added per week.
To find our when they will have equal amounts, write an equation with the two expressions:
5w + 5 = 4w + 12 Then solve for w.
5w -4w +5 -5 = 4w-4w +12 -5 Subtract 4w and 5 from both sides ("cancel" 0's)
w = 7
They will have equal amounts in the 7th week.
You can substitute 7 for w in the equation to check:
5(7) + 5 = 4(7) + 12
35 + 5 = 28 + 12
40 = 40 True! They will each have $ 40 in week 7.
