Check that 7 divides the sum 14 + 21 + 28.

Question

asked Aug 15, 2023 199k views

1 Answer

Pratap Sharma · Answer 1 · 2023-08-20T19:53:43+0000

Observed that 7 is a divisor of 14, 21 and 28.

So in effect:

$\bold{14 = 7 * 2}$

$\bold{21 = 7 * 3}$

$\bold{28 = 7 * 4}$

Thus, adding member by member the previous equalities, we would have:

$\bold{14 + 21 + 28 = 63 = 7 * 2 + 7 * 3 + 7 * 4}$

Taking out the common factor of 7 in the previous expression, we will have:

$\bold{4 + 21 + 28 = 7 * 9}$

I mean:

$\bold{14 + 21 + 28 = 7 * 9}$

That is to say, that 7 is a divisor of the sum
$\bold{14 + 21 + 28}$ since it is contained exactly 9 times in said sum.