The quality of the goods you produce depends on the quality of your production process. If your production process doesn’t meet the required quality standards, the product may be of inferior quality.
F(x)= x+13
F(-2)= -2 +13
= 11
You plug in -2 for the x
That's is depend from the author of the equation. But most time there is need to multiply value X into constant before.
In other words it look likes
y=2*x-3
