Question

simplify expression: -(-x+y-1)

Answer 1

write it as -1(-x+y-1)

Use Distributive Law, you get
x - y + 1

Answer 2

distributive property can also be: a(b + c + d) = a*b + a*c + a*d
so -1(-x + y -1) = (-1)(-x) + (-1)(y) + (-1)(-1)
= x - y + 1
the concept is the same
I like to think of it as what distributing means,
like if I were to distribute bread I would break it into pieces and give it out
so like if a was bread and b and c were who I gave it out to a(b + c),
distributive property would be I give a bread to b and a bread to c so a*b + a*c

Answer 3

ok...gotch...again much thanks

Answer 4

your welcome :)