Respuesta :

Answer:

7. n = 5r + 10

9.  [tex] 28.50j + 18s \le 100 [/tex]

Step-by-step explanation:

7.

The table gives you these values

2   20

4    30

6    40

8    50

The left side goes up by 2 each time while the right side goes up by 10 each line.

Using that pattern, fill in a few extra lines. I did it below in bold.

0    10

1     15

2   20

4    30

6    40

8    50

The line 0, 10 shows you that b in y = mx + b is 10. Also from the fist line to the second line, as x goes from 0 to 1, a difference of 1, y goes from 10 to 15, a difference of 5. The slope is difference in y over difference in x, so

slope = m = 5/1 = 5.

The equation is

y = mx + b

y = 5x + 10

The problem uses n instead of y and r instead of x, so you get

n = 5r + 10

9.

One pair of jeans costs $28.50. j is the number of jeans. j number of jeans cost 28.50j.

One shirt costs $18. s is the number of shirts. s number of shirts cost 18s.

The total cost is the cost of the jeans plus the cost of the shirts.

The total cost is 28.50j + 18s.

She can spend up to $100. The total cost of the jeans and shirts can be less than $100 or exactly $100, but it cannot be more than $100.

cost of jeans and shirts must be less than or equal to $100

[tex] 28.50j + 18s \le 100 [/tex]