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Re: ax + by=10, ay + bx=12. which one is greater here, x or y ?

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blueseas wrote:
Asifpirlo wrote:
ax + by=10
ay + bx=12

which one is greater here, x or y ?

(1)a > b
(2)a/b > 1



ax + by=10
bx + ay=12

subtracting these 2

(b-a)x + (a-b)y =2
or
(a-b)x - (a-b)y = -2
(a-b)(x-y) = -2

statement 1:
a>b and
(a-b)(x-y) = -2
(+)*(-)= -ve
therefore x-y<0
hence x<y
sufficient

statement 2:
a/b>1
(a-b)/b > 1
now a-b can be positive or negative
hence insufficient

hence A


Can you please explain a little bit more about the statement 2. How did you arrive at (a-b) ? I solved it as follows:
\frac{a}{b} >1
Multiply both sides by b.
a>b
This is the same as Statement 1. Hence the answer is D. Please clarify the answer.

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