Answer:
f(x) = 12x - 4
Step-by-step explanation:
f(x)= 20 + 12(x - 2)
Distribute
f(x) =20 +12x - 24
Combine like terms
f(x) = 12x+20-24
f(x) = 12x - 4
Hmm they're both even numbers so maybe we can start by cutting each number in half.

18 and 48 had 2 as a common factor.
So factoring a 2 out of each number was the same as cutting each number in half. Try to do something similar with the 9 and 24. They each have something in common.
Check the picture below. So let's use those two points on the line.

bearing in mind that the standard form is also a general form.
standard form for a linear equation means
• all coefficients must be integers, no fractions
• only the constant on the right-hand-side
• all variables on the left-hand-side, sorted
• "x" must not have a negative coefficient