Step-by-step explanation:
remember a few things :
a × -1 = -a
-a × -1 = a
-1 × -1 = 1
1 × a = a
therefore,
-1 × -1 × a = 1 × a = a
and finally
c × (a + b) = c×a + c×b
so, we can say
(1 - 5) = -1 × -1 × (1 - 5) =
= -1 × (-1×1 + -1×-5) = -1 × (-1 + 5) =
= -1 × (5 - 1) = -(5 - 1)
