x + 10 = 10 + 80
tính nhanh :
50 x 10 + 50 x 10
10 x 20 + 80 x 10
50 x 10 + 50 x 10
= (50 + 50) x 10
= 100 x 10
= 1000
10 x 20 + 80 x 10
= (20 + 80) x 10
= 100 x 10
= 1000
\(50.10+50.10\)
\(=500+500\)
\(=1000\)
\(10.20+80.10\)
\(=10.\left(20+80\right)\)
\(=10.100\)
\(=1000\)
50 x 10 + 50 x 10
= 500 + 500
= 1000
10 x 20 + 80 x 10
= 10 x ( 20 + 80 )
=10 x 100
= 1000
Tính nhanh
1,6 x 12 + 8 x 4,1 - 10 : 10/8 + 8/10 x 13 + 80% x 32
x+ 10 = 80 -10
x + 10 = 80 - 10
x + 10 = 70
x = 70 - 10
x = 60
x + 10 = 80 - 10
x + 10 = 70
x = 70 - 10
x = 60
1-4+7-10+ ... -x=-75
-8+13-...+x=250
2-6+10-14+...-x=-80
20 + 60 + 50 + 80 + 90 + 10 + 50 + 60 x 10
20 + 60 + 50 + 80 + 90 + 10 + 50 + 60 x 10
= (20 + 80) + (50 + 50 ) + (90 + 10 ) + 600 + 60
= 100 + 100 + 100 + 660
= 960
=(20+80)+(50+50)+(90+10)+(60*10)+60
=100+100+100+600+60
=960
20 + 60 + 50 + 80 + 90 + 10 + 50 + 60 x 10
= 20 + 60 + 50 + 80 + 90 + 10 + 50 + 600
= ( 20 + 80 ) + ( 50 + 50 ) + ( 90 + 10 ) + 60 + 600
= 100 + 100 + 100 + 60 + 600
= 100 . 3 + 660
= 300 + 660
= 960
10. 2 1/2 x 7/5 + {-9/10} x 2/3
11. X + 45% = 2 1/2 -5/3
12. 80% + X = -5/2 + 3/4
13. 4/25 - X =-5/2 + -3/10
`2 1/2 xx 7/5 + (-9/10) xx 2/3`
`= 5/2 xx 7/10 + (-9/10) xx 2/3`
`= 35/20 + (-18/30)`
`= 7/4 + (-3/5)`
`= 23/20`
__
`x + 45% =2 1/2 - 5/3`
`=> x+ 45/100 = 5/2 - 5/3`
`=>x+ 9/20= 15/6-10/6`
`=> x+9/20 = 5/6`
`=>x= 5/6 - 9/20`
`=>x=23/60`
__
`80% +x=-5/2 +3/4`
`=> 80/100 + x= -10/4 +3/4`
`=> 4/5 + x= -7/4`
`=>x= -7/4-4/5`
`=>x=-51/20`
__
`4/25 -x=-5/2 +(-3/10)`
`=> 4/25 -x= -25/10 +(-3/10)`
`=> 4/25 -x= -28/10`
`=>x= 4/25 -(14/5)`
`=>x= 4/25 + 14/5`
`=>x=74/25`
20 x 10 + 20 x 10 + 20 x 80
ai k mik mik k lại
20 x 10 + 20 x 10 + 20 x 80
= 20 ( 10 + 10 + 80 )
= 20 x 100
= 2000
tk mk nha !
20 x 10 + 20 x 10 + 20 x 80
= 20 x (10 + 10 + 80)
= 20 x 100
= 2000
ai k mik mik k lại
20 x10 + 20 x10 +20 x80
= 20 x ( 80 + 10 + 10 )
= 20 x ( 80 + 20 )
= 20 x 100
= 2000
Nho k minh nha
Bài 1:Tìm x;y;t biết :
x/10=12/y=63/10=t/80
tính nhanh : 10 x 20 -100 x 75 + 10 x 80 - 100 x 25
kban vs mk nha
10 . 20 - 100 . 75 + 10 . 80 + 100 . 25
= 10 . ( 20 + 80 ) - 100 . ( 75 + 25 )
= 10 . 100 - 100 . 100
= 1000 - 10000
= - 9000
10 x 20 -100 x 75 + 10 x 80 - 100 x 25
10. 10. 2 - 100. 75 + 10. 10. 8 - 100 .25
100.2 -100.75 +100.8 - 100.25
200 - 7500 + 800 - 2500
vô lý
10x20-100x75+10x80-100x25
200-7500+800-2500
-9000