420 + 65 . 4 = ( x + 175 ) : 5 + 30
420 + 260 = ( x + 175 ) : 5 + 30
680 = ( x + 175 ) : 5 + 30
680 - 30 = ( x + 175 ) : 5
650 = ( x + 175 ) : 5
650 . 5 = x + 175
3250 = x + 175
x = 3250 - 175
x = 3075
420+260=(x+175):5+30
680=(x+175):5+30
680-30=(x+175):5
650x5=x+175
3250=x+175
X=3250-175
X=3075
\(420+65.4=\left(x+175\right):5+30\)
\(680=\left(x+175\right):5+30\)
\(\left(x+175\right):5=680-30\)
\(\left(x+175\right):5=650\)
\(x+175=650.5\)
\(x+175=3250\)
\(x=3250-175\)
\(x=3075\)
420 + 65 . 4 = ( x + 175 ) : 5 + 30
420 + 260 = ( x + 175 ) : 5 + 30
680 = ( x + 175 ) : 5 + 30
680 - 30 = ( x + 175 ) : 5
650 = ( x + 175 ) : 5
650 . 5 = x + 175
3250 = x + 175
x = 3250 - 175
x = 3075
420 + 65 . 4 = ( x + 175 ) : 5 + 30
420 + 260 = ( x + 175 ) : 5 + 30
680 = ( x + 175 ) : 5 + 30
680 - 30 = ( x + 175 ) : 5
650 = ( x + 175 ) : 5
650 . 5 = x + 175
3250 = x + 175
=> x + 175 = 3250
x = 3250 - 175
x = 3075
Bài này trình bày khá dài ấy chứ :)