Alexis took an elevator one floor down from the lobby of her office building to the parking garage. then she took the elevator back up 5 floors to her office. she described her movement with this expression: 1+5 what was alexis’ error? she should have used –1 for moving below the lobby. she should have used –5 for moving up 5 floors. she should have used –1 for her movement down and –5 for her movement up. she should have started at zero and then added 6.

Her mistake was that she should have used –1 for moving below the lobby.

Step-by-step explanation:

Lets denote the lobby as Floor zero (0)

- if you go up, you add a positive value to this quantity.

- if you go down, you add a negative value to this quantity.

Lets assume that moving through each floor is equivalent to advancing one unit

* She first took an elevator one floor down

(-1)

Then she took the elevator back up 5 floors to her office

(+5)

Her movement is described by the expression

(-1) + (5)

Her mistake was that she should have used –1 for moving below the lobby.

3.4 pizzas

step-by-step explanation:

given is a scatter plot showing number of pizzas sold during weeks for different issues of coupon

y represents number of pizzas sold and x number of coupons issued

y is marked verticaly and x horizontally

the trend line is given as

y =3.4x+43

this says that even when no coupon is issued pizzas sold will be 43

and rate of change of pizza sold for 1 unit of coupon = slope = 3.4

i.e. when x increases by 1 unit y increases by 3.4 units

hence for each additional coupon issued 3.4 pizzas more will be sold