Question

найти неизвестное число
5/6+x=7/8+1/4
x+(1/7+2/3)=20/21
(7/6-1/2)+x=8/9

Answer 1

5/6+х=7/8+1/4
5/6+х=1 1/8
х=1 1/8-5/6
х=7/24

х+(1/7+2/3)=20/21
х+17/21=20/21
х=20/21-17/21
х=1/7

(7/6-1/2)+х=8/9
2/3+х=8/9
х=8/9-2/3
х=2/9