Question

If $9a+5B$ is divisible by 14, then prove that $5B+9a$ is also divisible by $14$.

Answer 1

Given that,

$9a+5B$ is divisible by 14

Let, and

Then,

$9a+5B=9\times 1+5\times 1=14$

Which is divisible by 14

Now,

Put $a=1$ and B=1 in $5B+9a$

$\Rightarrow 5B+9a=5\times 1+9\times 1=14$

Which is divisible by 14

Hence, proved