Question

Eric has a gift card to his favorite restaurant. Every Tuesday he has the same meal at the restaurant.



What is the equation that represents Eric's gift card balance? Record any fractional answers in decimal form.



(y -100) =___(x - ___ )


Eric's Gift Card
Weeks 2 4 6 8
Balance$125 $100 $75 $50

Answer 1

you can calculate the change or plot the graph and see the change is $-75/2 weeks
using the point slope formula
the point in the equation has a y value of 100

Answer 2

m = slope = change in y/ corresponding change in x
m = (Y2 - y1)/(x2 - x1) using 2 points (x1,y1) and (x2, y2) on that line

Answer 3

* not -75 -25

Answer 4

find the slope by using the slope formula : slope(m) = (y2 - y1) / (x2 - x1)
using 2 of your points....any 2
(2,125)...x1 = 2 and y1 = 125
(4,100)...x2 = 4 and y2 = 100
now sub into the formula to find the slope

Answer 5

let me get you started..
slope(m) = (100 - 125) / (4 - 2)
can you find the slope now ?

Answer 6

that / is the division symbol?

Answer 7

yes..but leave it as a fraction

Answer 8

-25/2

Answer 9

correct...so that is your slope.
Now we will use point-slope formula
y - y1 = m(x - x1)

Answer 10

y - y1 = m(x - x1)
slope(m) = -25/2
It looks like your answer already has 100 as y....so we will use points (4,100)..x1 = 4 and y1 = 100.
Now we sub
y - 100 = -25/2(x - 4) <== your answer

any questions ?

Answer 11

thank you so much! that was surprisingly easy...

Answer 12

it is not as hard as it looks...lol
glad I could help :)

Answer 13

i got it wrong, it was 12.5...

Answer 14

@GirlgoyleH do you understand why you got it wrong?

Answer 15

you did not follow the directions.
Record any fractional answers in decimal form.
-25/2 = negative 12.5

Answer 16

@triciaal so the answer would be (y-100)=12.5(x-4)?

Answer 17

yes

Answer 18

dont forget the - on 12.5