Question

Soos is spending money at the average rate of $5 per day. After 9 days, he has $25 left.

Answer 1

Answer:  She had $70 at the beginning.

Step-by-step explanation:

Lets represent this situation as an equation where we will  use y to represent the amount of money left and x for the number of days.  

Using the formula  y = mx + b  , we can say b  will be the amount in 0 days because its the y intercept and the y intercept is when x is 0.  

m will be the rate of change and the rate of change will be -5 per day because he is spending.

In 9 days, he had $25 left  and we can also represent that by the point (9,25)  

Now input the values for x and y into the formula with the slope and solve for b.

y = mx + b

25 = -5(9) + b

25 =  - 45 + b    

+45    +45

 b = 70  

This means she started with $70.

Answer 2

to get the answer you first need to do is $5 × 9 and that will get you $45. then you add the $25 to the $45