χ-2,3=3,6

(a)  

230-χ=45,82

(a)  

30χ=6

(a)  

0,40x=6,2

(a)  

x:36=0,07

(a)  

6⁄3 ÷ χ =5

(a)  

220,5-x=14,8

(a)  

6,44:x=14

(a)  

χ ÷ ⅛ = 2²

(a)