which is true ?

Question

let a and b be any positive integers and x=0 or 1,then

a)a^xb(1-x)=x*a+b(1-x)
b)a^xb(1-x)=a(1-x)+x*b
c)a^x*b(1-x)=a*(1-x)*b*x
d)None of these necessarily true

is this question not clear ?

my book has given only the answer but no explanation....the book has suggested to use "method of substitution"

but as you see, its difficult to use what to substitute .

BTW, any have a nice answer ?

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hmm...none of the answer so far matches with my book.....

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anser given is (a)

Answer 1

_________a)a^xb(1-x)=x*a+b(1-x)
4 x=1
lhs = 0; rhs = 0

4 x=0
lhs = b; rhs = 0

__________b)a^xb(1-x)=a(1-x)+x*b
4 x = 1
lhs = 0; rhs = b

4 x = 0
lhs = b; rhs = a

____________c)a^x*b(1-x)=a*(1-x)*b*x
4 x = 1
lhs = 0; rhs = 0

4 x = 0
lhs = b; rhs = 0






none is true. ur ans is D

Answer 2

options a) and b) are incorrect since the left hand side of both equations will always be 1 either x=0 or 1,since it will always equal a^0, while the right hand side may equal either a or b.
option c) is also incorrect because, as i assumed that the right hand side is a^(1-x)*bx, when x=0, then b=0, while when x=1, then also b=0. And as you said, b is a positive integer.
so none of the above options is necessarily true, which is option d).

Answer 3

Why not go to a homework help site?

P.S. If you had listened in class, you would not have had to go to summer school and you would also know the answer!

Answer 4

hu what in the world

Answer 5

Option (e)

Answer 6

ans:(D)

Answer 7

wtf?