Toán Lớp 6: Tìm x N biết : a) (x – 15 ) – 75 = 0 b) 575- (6x +70) =445 c) 315+(125-x)= 435

Question

Toán Lớp 6:  Tìm x  N biết : a) (x – 15 ) – 75 = 0              b) 575- (6x +70) =445                  c) 315+(125-x)= 435

mytamhoang · Answer

Bài làm :   a ) (x-15)-75=0        (x-15)     =0+75        x-15       =75        x             =75+15        x             =90    V&acirc;̣y x = 90    b)  575- (6x +70) =445                  (6x +70) = 575-445                 (6x +70)  = 130                 6x +70   =130                6x            =130-70                6x            =60                   x           =60:6                   x           =10     V&acirc;̣y x =10     c)  315+(125-x)= 435                   (125-x)=435-315                  (125-x)=120                          x= 125- 120                         x = 5     V&acirc;̣y x = 5       Xin hay nh&acirc;́t ạ !

thanhmaianh · Answer

#huy a) (x – 15 ) – 75 = 0 <=>x-15-75=0 <=>x-90=0 <=>x=90 b) 575- (6x +70) =445 <=>6x+70=575-445=130 <=>6x=130-70=60 <=>x=10 c) 315+(125-x)= 435 <=>315+125-x=435 <=>440-x=435 <=>x=440-435 <=>x=5