Question 1205221
{{{a}}} ≡{{{ -25 (mod 7)}}}

What is the remainder when you divide {{{-25}}} by {{{7}}}?

{{{-25 / 7}}} ≈ {{{-3.571429}}}=>  round it to  {{{-4}}}


then

{{{-25 + (-4*7)=-25+28 = 3}}}

the answer is: {{{a=3 (mod 7)}}}