Answer:

P.S. If u want a numerical value for 'f' , now put the value of 'm'
X^2 - 8x + 13 = 0
subtract 13 from both sides
x^2 - 8x = -13
-8/2 = -4, (-4)^2 = 16, add 16 to both sides
x^2 - 8x + 16 = -13 + 16
factor the left side
(x - 4)^2 = 3
ANSWER
a=-2, b=3
EXPLANATION
The given equation is

Recall that:

We simplify the left hand side to get:

For this equation to be true, we must have:
-6a=12 and 2+b=5
This implies that,
a=-2 and b=3