LCD is least common denominator. So looking at the denominators, their factors are...
First term x^2 - 5x + 4 = (x - )( x - ). We know this because the 4 (c term)is + so both signs are the same, and both are NEGATIVE because 5 (b term) is -
= (x - 4)(x - 1) because(-1)(-4) = 4 (c term) and -1 + -4 = -5 (b term)
