What is the slope-intercept form of the function described by this table?

y = -4x +2

The slope-intercept form of the equation for a line is conveniently found from the point-slope form. In either case, you need to know the slope. That is ...

... slope = m = (change in y)/(change in x)

For the first two points, the slope is ...

... m = (-6 -(-2))/(2 -1) = -4

Using the point-slope equation for slope m and point (h, k) written as ...

... y = m(x -h) +k

we can substitute m = -4 and (h, k) = (1, -2) to get ...

... y = -4(x -1) -2

... y = -4x +2 . . . . . . . simplify

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