ПОМОГИТЕ! 3.4+(5,2-9)=? 6 5/6-(2 1/4+5/6)=? m*4.5*4=? 12m-m+9m=? УРАВНЕНИЕ 0,2x-1,4X=6

Question

ПОМОГИТЕ!
3.4+(5,2-9)=?
6 5/6-(2 1/4+5/6)=?
m*4.5*4=?
12m-m+9m=?
УРАВНЕНИЕ
0,2x-1,4X=6

Answer 1

3.4+(5,2-9)=3,4+(-3,8)=-0,4
6 5/6-(2 1/4+5/6)= 6 5/6 - (2 3/12 + 10/12)= 6 5/6 - 2 13/12 = 6 5/6 - 3 1/12 = 6 10/12 - 3 1/12 = 3 9/12 = 3 3/4 
m*4.5*4=18m
12m-m+9m=20m
0,2x-1,4X=6
-1,2х=6
х=6:(-1,2)
х=-5

Answer 2

3.4+(5,2-9)=3,4+(-3,8)=3,4-3,8=-0,4
65/6-(21/4+5/6)= 65/6 - (23/12 + 10/12)= 65/6 - 213/12 = 6 5/6 - 31/12 = 610/12 - 31/12 = 39/12 = 13/4=3,25
m*4.5*4=m18=18m
12m-m+9m=11m+9m=20m
0,2x-1,4X=6
-1,2х=6
-х=6:1,2
-х=5  
x=-5