X + X x 2 = 345
=> X x ( 1 + 2 ) = 345
=> X x 3 = 345
=> X = 345 : 3
=> X = 115
vậy X = 115
Giải
X+X*2=345
1*X+X*2=345
X*(1+2)=345
X=345:3
X=115
X+Xx2=345
\(\Rightarrow\)Xx3=345
X=345\(\div\)3
X=115
X+Xx2=345 Xx(1+2)=345 X x 3=345 X=345:3=115,TK MIK NHA ! MIK TRA LOI DAU TIEN !
X + X x 2 = 345
X x ( 2 + 1 )
X x 3 = 345
X = 345 : 3
X = 115