I was doing some problems for Olympiad training and encountered this: How would you prove that
$(a+b+c+d)-(a+c)(b+d)\geq 1$?
We are told that $0 and the product $abcd=(1-a)(1-b)(1-c)(1-d)$.
Thanks!!
I was doing some problems for Olympiad training and encountered this: How would you prove that
$(a+b+c+d)-(a+c)(b+d)\geq 1$?
We are told that $0 and the product $abcd=(1-a)(1-b)(1-c)(1-d)$.
Thanks!!