125+18=143
12×125×54
b.64×125×54
c.36×[143+57)+64+(143+57)
d.78×31+78×24+70×22×22×72
e.64×14+9×59
\(a.12\times125\times54\)
\(=1500\times54\)
\(=81000\)
\(b.64\times125\times54\)
\(=8000\times54\)
\(=432000\)
\(c.36\times\left[143+57\right]+64+\left(143+57\right)\)
\(=36\times200+64+200\)
\(=7200+64+200\)
\(=7264+200\)
\(=7464\)
a) =81000
b) 432000
c) 7464
d) 7414
e) 1427
cam on cac ban nhieu nhe lan sau co bai toan nho giup do minh nhe ban
bài 1 : tính nhanh
(145 x 99 + 145) - (143 x 102 - 143)
54 x 47 - 47 x 53 - 20 - 27
2 x 8 x 50 x 25 x 125
tính nhanh
a) 45+45+45+45+15+15+15+15=
b) 125+125+125+125-25-25-25-25=
c) (145x99+145) -( 143x102-143) =
d) 54x47-47x53-20-27=
e)326x728+327x272=
a.45+45+45+45+15+15+15+15=45×4+15×4=4×(45+15)=4×60=240
125+125+125+125-25-25-25-25=125×4-25×4=4×(125-25)=4×100=400
Tính nhẩm :a)400:25 b)864:125 c)165:15 d)143:13
\(a,400:25=16\)
\(b,864:125=6,912\)
\(c,165:15=11\)
\(d,143:13=11\)
212 . 35 - 46 . 92 510 . 73 - 255 . 492
______________ - ____________________
(22 . 3)6 (125 . 7)3 + 59 . 143
\(=\dfrac{2^{12}\cdot3^4\left(3-1\right)}{2^{12}\cdot3^6}-\dfrac{5^{10}\cdot7^3\left(1-7\right)}{5^9\cdot7^3+5^9\cdot7^3\cdot2^3}\)
\(=\dfrac{-2}{9}-\dfrac{5\cdot\left(-6\right)}{9}=\dfrac{-2-5\cdot\left(-6\right)}{9}=\dfrac{-2+30}{9}=\dfrac{28}{9}\)
bo ngoac roi tinh
- (-15) – (-3 +15 – 8)
b) + ( - 143 + 17 – 35) – ( -143 + 37 – 35)
c) 50 – (47 + 50 – 18) - (+47 + 18)
d) 16 – (-15) + (-20) - | -24 |
- (-15) – (-3 +15 – 8)
= 15 + 3 - 15 + 8
= 11
b) + ( - 143 + 17 – 35) – ( -143 + 37 – 35)
= -143 + 17 - 35 + 143 - 37 + 35
= -20
c) 50 - ( 47 + 50 - 18 ) - ( 47 + 18 )
= 50 - 47 - 50 + 18 - 47 - 18
= -47 - 47
= -94
d) 16 - ( -15 ) + ( -20 ) - | -24 |
= 16 + 15 - 20 - 24
= -13
a, -(-15) - ( -3 + 15 - 8 ) = 15 - 3 + 15 + 8
= 12 + 15 + 8
= 27 + 8
= 35
b, + ( -143 + 17 - 35 ) - ( -143 + 37 - 35 )
= -143 + 17 - 35 + 143 - 37 + 35
= ( -143 + 143 ) + [ 17 + (-37 )] + ( -35 + 35)
= 0 + 20 + 0
= 20
c, 50 - ( 47 + 50 -18 ) - ( +47 + 18 )
= 50 - 47 - 50 + 18 - (-47) - 18
= ( 50 - 50 ) - [ 47 - (-47)] + (18 - 18 )
= 0 - 0 + 0
= 0
d, 16 - (-15) + (-20) -I -24 I
= 16 + 15 - 20 + 24
= 30 - 20 + 24
= 10 + 24
= 34
tính thuận tiện
a ( 145 * 99 - 145 ) - ( 143 * 101 - 143 )
b ( 500 * 9 - 250 * 18 ) * ( 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 +9 )
c ( 11 + 12 + 13 + 14 + 15 + 16 + 17 + 18 + 19 ) * ( 6 * 8 - 48)
c) \(\left(11+12+13+...+19\right).\left(6.8-48\right)=\left(11+12+13+...+19\right).\left(48-48\right)\)
\(=\left(11+12+13+...+19\right).0\)
\(=0\)
Hok "tuốt" nha^^
b) \(\left(500.9-250.18\right).\left(1+2+3+...+9\right)=\left(250.2.9-250.18\right).\left(1+2+...+9\right)\)
\(=\left(250.18-250.18\right).\left(1+2+3+...+9\right)\)
\(=0.\left(1+2+3+...+9\right)\)
\(=0\)
Hok tốt nha^^ (lần 2)
tính giá trị biểu thức
a. 789 nhân 78 + 788 nhân 22
b. 4 nhân 113 nhân 25 - 5 nhân 112 nhân 20
c.[145 nhan 99+145]-[143 nhan 101 -143 ]
d. 4 nhan 125 nhan 25 nhan 8
Ghi từng cái thôi ! Ghi nhiều thế làm mỏi cả tay !!!
Tính tổng :
a) ( -125 ) + 100 + 80 + 125 + 20
b) 27 + 55 + (-17) + ( -55)
c) (-92) + (-251) + (-8) +251
d) (-31 ) + (-95) + 131 + (-5)
e) ( 187 - 23) - (20 -180)
g) (-50 + 19 + 143 ) - (- 79 + 25 + 48)
a) ( -125) + 100 + 80 + 125 + 20
= [ ( -125)+125] + ( 80+20) + 100
= 0 + 100 + 100 = 200
b) 27 + 55 + (-17) + ( - 55)
= [ 27+(-17)] +[ 55+(-55)]
= 10 + 0 = 10
c) (-92) + (-251) + (-8) + 251
= [ (-92) + (-8)] + [ (-251)+251]
= (-100) + 0 = -100.
d) (-31) + (-95) +131 + (-5)
= [ (-31)+131] +[ (-95)+(-5)] = 100 + (-100) = 0
e) (187 - 23) - (20-180)
= 187 - 23 - 20 + 180 = (187-180) - (23-20) = 7 - 3 = 4
g) (-50+19+143) - (-79+25+48)
= -50+19+143 + 79 - 25 - 48
= [ -50-25] + (19 + 79) + 143 - 48
= -75 + 98 + 143 - 48 = 143 - 75 + ( 98 -48)
= 68 + 50 = 118