a) 647 + 238 + 533 + 762 + 3465
b) 1234 + 5678 + 4321 + 8765
2 tìm x
x-105 : 5 = 21
( x – 105 ) : 5 =21
( x-48) : 2 – 4 =21
( x + 321 ) : 8 – 125 = 25
( 12x – 144 ) – 240 = 360
gips mình nha cảm ơn nhé
a) 647 + 238 + 533 + 762 + 3465
b) 1234 + 5678 + 4321 + 8765
2 tìm x
x-105 : 5 = 21
( x – 105 ) : 5 =21
( x-48) : 2 – 4 =21
( x + 321 ) : 8 – 125 = 25
( 12x – 144 ) – 240 = 360
gips mình nha cảm ơn nhé
Bài 1:
a,647+238+533+762+3465=(647+533)+(238+762)+3465
=1180+1000+3465
=5645
b,1234+5678+4321+8765=6912+13086
=19998
Bài 2:
a,x-105:5=21
x-21 =21
x =21+21
x =42
b,(x-105):5=21
(x-105)=21.5
x-105=105
x=105+105
x=210
c,(x-48):2-4=21
(x-48):2=21+4
(x-48):2=25
x-48=25.2
x-48=50
x=50+48
x=98
d,(x+321):8-125=25
(x+321):8=25+125
(x+321):8=150
x+321=150.8
x+321=1200
x=1200-321
x=879
e,(12x-144)-240=360
(12x-144)=360+240
12x-144=600
12x=600+144
12x=744
x=744:12
x=62
CHÚC BẠN HỌC TỐT>_<!
Đáp án:
Giải thích các bước giải:
a.647+ 238+ 533+ 762+ 3465
=885+1295+3465
=2180+3465
=5645
b,1234+5678+4321+8765
=6912+13086
=19998
2.tìm x
x-105:5=21
x-21=21
x=21+21
x=42
(x-105} :5=21
x-105=21 x 5
x-105=105
x=105+105
x=210
(x-48} : 2 -4 =21
(x-48} : 2=21+4
(x-48} : 2=25
x-48= 25 x 2
x-48= 50
x=50-48
x=2
(x+321} :8 -125 =25
(x+321} : 8=25+ 125
(x+321} : 8=150
x+321=150x 8
x+321=1200
x=1200-321
x=879
(12x-144} -240 =360
(12x-144}=360+240
(12x-144}=600
12x=600+144
12x=744
x=7412
x=62
CHÚC BẠN HỌC TỐT