9514 1404 393
Answer:
a. $850
b. 7 weeks
c. f(x) = 125x +475
d. see attached (3, 850), (7, 1350)
e. 53 weeks
Step-by-step explanation:
After 3 weeks, $125×3 = $375 will have been added to the $475 already in the account. The balance will be ...
$375 +475 = $850
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The student will have to add $1350 -475 = $875 to her account to reach $1350. At a rate of $125 per week, that will take ...
$875/($125/week) = 7 weeks
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The initial value is $475, and the rate of change is $125 per week, so the equation can be written ...
f(x) = 475 +125x . . . . . . . balance after x weeks
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See the attached graph with the required points marked. (3, 850), (7, 1350)
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It will take more than 53 weeks for the student to reach her goal. (After 52 weeks, the account will have $6975, so will be $25 short of the goal.)