Rates like $ per channel is a slope, "m". The added fee is a constant so it's the intercept "b".
y = mx + b
So for the first problem (9)
(a)
y = total cost in dollars
x = number of premium channels
y = 16x + 44
(b) when x = 3 channels
y = 16(3) + 44
y = 92 $
the second problem (10)
(a) every 4 years the tree grows by 12-9=3 ft
So the unit rate or slope will be 3 ft per 4 yrs, (3/4). You can see this also by solving for slope "m" using the given points (4,9) and (8,12).
x = number of years
y = height of tree in ft
y = (3/4)x + b
use one of the points to find the y-intercept "b".
9 = (3/4)(4) + b
9 = 3 + b
9 - 3 = b
6 = b
y = (3/4)x + 6
(b) when x = 16
y = (3/4)(16) + 6
y = 12 + 6
y = 18 ft
The anwser is for the question tht u are looking for is no other then the first anwser A!!!
To isolate b, add a and subtract c to the entire equation:
D - a + c = -b
Muliply b by -1 to eliminate the negative:
-D + a - c = b
