34+(21-x)=3747-30-3746
21-x=(3747-3747)-(30+34)
21-x=1-64
x=21-(-63)=21+63
x=84
34+(21-x) =(3747-30)-3746
34+(21-x)=3717-3746
34+(21-x)= -29
21-x=-29-34
21-x=-63
x=21-(-63)
x= 21+63
x=84
Tick nha
34+(21-x)=(3747-30)-3746
=>34+(21-x)=-29
=>21-x=34-(-29)=63
=>x=21-63=-42
vậy x=-42
mk nhầm, giải lại:
34+(21-x)=(3747-30)-3746
=>34+(21-x)=-29
=>21-x=-29-34=-63
=>x=21-(-63)=84