Question

Sebastian saved money in his piggy bank. He kept track on how much money he saved at the end of each week on the line graph below.

How much money had Sebastian saved by the end of seven weeks?

Answer 1

X: weeks
Y: total amount saved

(2,30) (4,40)

M=40-30. 10
———- = —- = 5
4-2 2

Y=5x + B
30= 5(2) + B
30=10 + B
-10 -10
20= B


Y= 5x+20
Y= 5(7) + 20
Y= 35+20
Y=55$ Amount saved.

Answer 2

$90

Explanation:

Look at the number 7 on the bottom right of the graph. That means at the end of 7 weeks. Now look vertically up from there until you see a point directly above 7 weeks. Look to the left of that point, and you see that the point directly above 7 weeks is at the level of $90. That means that at the end of 7 weeks, he had $90.