Respuesta :
remember
ab+ac=a(b+c)
if we reverse it
ba+ca=a(b+c)
so
c(m-n)+d(m-n)=(m-n)(c+d)
(c+d)(m-n)
C is answer
ab+ac=a(b+c)
if we reverse it
ba+ca=a(b+c)
so
c(m-n)+d(m-n)=(m-n)(c+d)
(c+d)(m-n)
C is answer
the answer is (c+b)(m-n) because m-n is on both sides of the + and so they can be added together making it easier to figure out if you have the numbers to replace the variables.