X = 7 - y
x = -2y + 12

x=2, y=5. (2, 5).

Step-by-step explanation:

x=7-y

x=-2y+12

7-y=-2y+12

7-y-(-2y)=12

7-y+2y=12

7+y=12

y=12-7

y=5

x=7-5=2

walter needs to make at least 5 more cookies but no more than 40. 5 ≤ x ≤ 40

step-by-step explanation:

20 ≤ x + 15 ≤ 55

subtract 15 from all parts

20-15 ≤ x + 15-15 ≤ 55-15

5 ≤ x ≤ 40

this means how many more cookies he has to make

walter needs to make at least 5 more cookies, but no more than 40 cookies; 5 ≤ x ≤ 40