6(11n+31)+9(17-3n)=417
66n+186+153-27n=417
39n+339=417
39 n=417-339
39 n=78
n=78÷39
n=2
6(11×2+31)+9(17-3×2)=417
417=417
6(11n+31)+9(17-3n)=417
66n+186+153-27n=417
39n+339=417
39 n=417-339
39 n=78
n=78÷39
n=2
6(11×2+31)+9(17-3×2)=417
417=417
66n+186+153-27n=417
39n+339=417
39n=417-339
39n=78
n=78÷39
n=2
ответ: n=2.