Math channel to convert sensor voltage to unit

Hi, need clarification that my math channel setting is correct. For my NOS control i need NOS pressure sensor input to safely turn on my NOS system.

The pressure sensor is linear sensor which i had identify gradient and Y-axis cross value (m= 40) and (c= -20),

y = mx+c

pressure (in bar) = 40*m - 20

Is there anyway i can use only single match channel to do this?

Right now i believe 2 channels can work. Below is my 2 channel match setup:

Get value of MX = 40*input_voltage

Final pressure in BAR = (Get value of MX) - 20

Thanks!

Zaihas