Упростить выражение 7,2х+1,8х 1/6х+1/2х 9,3х-1,4х 3/4х-1/2х 10х-6,7х х-4/5х

Упростим выражения: 1) 7,2х + 1,8х = х * (7,2 + 1,8) = х * 9 = 9х; 2) 1/6х + 1/2х = х * (1/6 + 1/2) = х * (1/6 + 3/6) = х * 4/6 = х * 2/3 = 2/3х; 3) 9,3х - 1,4х = х * (9,3 - 1,4) = х * 7,9 = 7,9х; 4) 3/4х - 1/2х = х * (3/4 - 1/2) = х * (3/4 - 2/4) = х * 1/4 = 1/4х; 5) 10х - 6,7х = х * (10 - 6,7) = х * 3,7 = 3,7х; 6) х - 4/5х = х * (1 - 4/5) = х * (5/5 - 4/5) = х * 1/5 = 1/5х.