Question

On February 2nd, Jordan is going on a class trip to Washington D.C. He is saving his weekly allowance to use as spending money while on the trip. Each week, Jordan's parents give him the $8 he earned for the week, and he records the total amount of money he has saved in the table below.

Week January 4 January 11 January 18 January 25 February 1
Total $ Saved $86 $94 $102
Which equation below is a linear model of the data presented in the table?
y = 8 x + 8.6
y = 86 x + 8
y = 8 x + 86
y = 8 x

Answer 1

y = 8x + 86

Reason: Jordan's total increases by $8 each week (slope = 8). At the start (January 4) he already had $86, so the y-intercept is 86. Checking: 8(1)+86 = 94 (Jan 11), 8(2)+86 = 102 (Jan 18).