(5n-3)^2-(5n+2)(5n-2)=-47
25n^2-30n+9 - (25n^2-4)=-47
25n^2-30n+9 - 25n^2+4=-47
-30n+13=-47
-30n=-60
n=2
ответ: n=2
(5n-3)^2-(5n+2)(5n-2)=-47
25n^2-30n+9 - (25n^2-4)=-47
25n^2-30n+9 - 25n^2+4=-47
-30n+13=-47
-30n=-60
n=2
ответ: n=2