Упростите выражение 415 9 × (2,7m-2 4 n)-4,2 ( 7 m-0,5n)=
4/9 * 27/10m - 4/9 * 9/4n - 21/5 * 5/7m + 21/5 * 1/2n = = 6/5m - n - 3m + 21/10 = = 1,2m - 3m - n + 2,1 = = -1,8m + 1,1n = 1,1n - 1,8m