51.7+2.86.7+12.2.7
tính nhanh
4.51.7+2.86.7+12.2.7
tính nhanh
=2x7(2x51+86+12)
=14.(102+86+12)
=14.200
=2800
Tính nhanh :
1.3 - 3.2 + 51.7 + 8.9 - 10.8 + 12.7 - 14.6 + 16.5
Tinh nhanh:
a) 4.51.7+2.86.7+12.2.7
b) 237 +301+183+219
a)
4 . 5 . 7 + 2 . 86 . 7 + 12 . 2 . 7
= 20 . 7 + 172 . 7 + 24 . 7
= 7 . (20 + 172 + 24)
= 7 . 216
= 1512
b)
237 + 301 + 183 + 219
= (237 + 183) + (301 + 219)
= 420 + 520
= 940
k mk nha DuongthiHongDuyen !
Tính nhanh
a) 41.36+59.90+41.81+59.30
b) 4.51.7+2.86.7+12.2.7
bài 2 : tìm x
a) (x-1954).5=50
b) 30.60-x=30
41.36+59.90+41.81+59.30=11877
4.51.7+2.86.7+12.2.7=2800
x=1964
x=1500
4.51.7+2.86.7+12.2.7
=2*2*51*7+2*2*7*43+2*2*7*6
=2*2*7*(51+43+6)
=28*100
=2800
Lưu ý: * là dấu nhân
Ok Chúc bạn học tốt
4.51.7+2.86.7+12.2.7
=1428+1204+168
=2800
4.51.7+2.86.7+2.7.12
4 . 51 . 7 + 2 . 86 . 7 + 2 . 7 . 12
= ( 4 . 51 ) . 7 + ( 2 . 86 ) . 7 + ( 2 . 12 ) . 7
= 204 . 7 + 172 . 7 + 24 . 7
= 7 . ( 204 + 172 + 24 )
= 7 . 400
= 2 800
4.51.7+2.86.7+12.2.7=?
4.51.7+2.86.7+12.2.7
= 2.7.2.51+ 2.2.7.43+ 2.2.7.6
=2.2.7 .( 51+43+6)
= 28 . 100
= 2800
\(4.51.7+2.86.7+12.2.7=\left(4.51.7\right)+\left(2.86.7\right)+\left(12.2.7\right)=1428+1204+168=2632+168=2800\)
4.51.7 + 2.86.7 + 12.2.7
= 2.2.51.7 + 2.7.86 + 2.7.12
= 2.7.102 + 2.7.86 + 2.7.12
= 2.7 ( 102 + 86 + 12)
= 14 . 200
= 2800
4.51.7+2.86.7+2.2.7
204*7+172*7+4*7=7*(204+172+4)=7*380=2660
4.51.7+2.86.7+12.2.7
Giải hộ ạ :3
=2.2.51.7+2.7.86+12.14
=2.51.14+14.86+14.12
=14.(102+86+12)
=14.202
=2828
\(4.51.7+2.86.7+12.2.7=2.7\left(2.51+86+12\right)=14\left(102+86+12\right)=14.200=2800\)