Question

If a>b and a(b-a)=0, which one or more of the following must be true?
i) a=0 ii) b<0 iii) a-b>0

Answer 1

if a(b-a) = 0
then either a=0 OR b-a =0
did u get this?

Answer 2

@Ventricate did u get how i got that?

Answer 3

anyways , lets continue
b-a=0 gives
b=a
but its given that a>b
so b-a=0 is NOT true
hence a=0 must be true

Answer 4

ya i get that but the answer key says all three is true

Answer 5

since a>b
and a=0
then b must be negative
so b<0

Answer 6

-b>0 (u flip the sign when you multiply by a negative quantity)
add a to both sides
a-b>a
and since a=0
a-b > 0

Answer 7

ahh makes more sense thank you!

Answer 8

welcome ^_^