Answer:
B. (m-1)(m-8)
Step-by-step explanation:
The factors of 8 (constant term) are
{(1,8), (2,4)}, from which we see that 1+8 = 9, the absolute value of the coefficient of the second term.
Therefore we can group the expression as
m^2 - 9m + 8
= m^2-m - (8m -8)
then factor each group
= m(m-1) - 8(m-1)
and factor out (m-1)
= (m-1)(m-8)
