This is the table=
A B
1 3.5 3.75
40 140 150
100 350 375
so more cheaper is printer A
Steps:
18 x 2
What is that?
You can also think of it as 9 x 4 if that is easier
Then whatever you got for that, add 21 then subtract 12 and add 1
A quadratic in vertex form can be represented as

a represents reflection over the x-axis, and a vertical stretch or compress
- is reflection and a fraction (1/2) represents a compression.
-h represents a shift of that many units to the right (-2 shifts to the
right two units)
k represents a shift up or down (-2 is shifting down 2 units_
Reflected over the x-axis, Vertically compressed by a factor of 1/2, shifted 2 units to the right, and shifted 2 units down