calculate : [ 247 * 315 + 246 * 314 ] * [ 98 * 47 - 94 * 49 ] = ...........
Tính : (247 x 315 + 246 x 314 ) x (98 x 47 -94 x49) = ?
( 247 x 315 + 246 x 314 ) x ( 98 x 47 - 94 x 49 )
= ( 247 x 315 + 246 x 314 ) x ( 4606 - 4606 )
= ( 247 x 315 + 246 x 314 ) x 0
= 0
(247 x 315 + 246 x 314) x (98 x 47 - 94 x 49)
= (247 x 315 + 246 x 314) x (4606 - 4606)
= (247 x 315 + 246 x 314) x 0
= 0
= ( 247 x 315 + 246 x 314 ) x ( 4606 - 4606 )
= (247 x 315 + 246 x 314 ) x 0
= 0
vì số nào nhân không cũng bằng 0
Tính nhanh.
a) (-4).(-8).(-17).(-25).125
b) (236 – 362) – (638 + 463)
c) (- 325 – 147) – ( - 625 + 853) – (-96)
d) 69.(- 47) – 31. (- 47)
e) 98. (- 37) + (- 49).126
f) – 35. (49 – 125) – 125 .(35 – 49)
g) 2 + 4 – 6 – 8 + 10 + 12 – 14 – 16 + …+ 90 + 92 – 94 – 96
h) 1 + 3 + 3 2 + 3 3 + ….+ 3 50
Đặt tính rồi tính.
a, 146 + 47 b, 213 – 106 c, 247 + 108 d, 315 -241
315/316×313/314×316/315×317/314
Đơn giản như đang giỡn :
=315.313.316.317/315.314.316.317
=313/314
hok tốt k nhé bạn .
\(\frac{315}{316}\cdot\frac{313}{314}\cdot\frac{316}{315}\cdot\frac{317}{314}\)
= \(\frac{315\cdot313\cdot316\cdot317}{316\cdot314\cdot315\cdot314}\)
=\(\frac{1\cdot313\cdot1\cdot317}{1\cdot314\cdot1\cdot314}\)(Bước này là bước rút gọn)
= \(\frac{99221}{98596}\)
#Kiều
\(\frac{315}{316}.\frac{313}{314}.\frac{316}{315}.\frac{317}{314}\)\(=\frac{315.313.316.317}{316.314.315.314}\)
Sau khi rút gọn:
\(=\frac{313.317}{314.314}\)
Tính:
a, - ( -315) + ( -115) - 105 + 25
b, 85 + ( -185)
c, 215 + [ 144 - ( 144 - 215) ]
d, ( -98) . (1 - 246) - 246 . 98
e, A = [ ( -20) + (-8) ] + [ ( -7) +3 ]
f, B = \(\frac{1}{2}-\frac{5}{7}.\frac{14}{25}\)
ra kết quả thui nhé!
a/ 120
b/ -100
c/ 430
d/ -98
e/ A=-32
f/ B=1/10
tik nhá
a, Cho A= 1/99 + 2/98 + 3/47 + .......... + 98/2 + 99/1
B= 1/2 + 1/3 + 1/4 + ..........+ 1/99 + 1/100
Tính B/A
b, Cho A= 1/49 + 2/48 + 3/47 +.......+ 48/2 +49/1
B= 1 + 2/3 + 2/4 +......+ 2/49 + 2/50
Tính A/B
a: \(A=\left(\dfrac{1}{99}+1\right)+\left(\dfrac{2}{98}+1\right)+...+\left(\dfrac{98}{2}+1\right)+1\)
\(=\dfrac{100}{99}+\dfrac{100}{98}+...+\dfrac{100}{2}+\dfrac{100}{100}\)
\(=100\cdot\left(\dfrac{1}{2}+\dfrac{1}{3}+...+\dfrac{1}{100}\right)\)=100B
=>B/A=1/100
b: \(A=\left(\dfrac{1}{49}+1\right)+\left(\dfrac{2}{48}+1\right)+\left(\dfrac{3}{47}+1\right)+...+\left(\dfrac{48}{2}+1\right)+\left(1\right)\)
\(=\dfrac{50}{49}+\dfrac{50}{48}+....+\dfrac{50}{2}+\dfrac{50}{50}\)
\(=50\left(\dfrac{1}{2}+\dfrac{1}{3}+...+\dfrac{1}{50}\right)\)
\(B=\dfrac{2}{2}+\dfrac{2}{3}+\dfrac{2}{4}+...+\dfrac{2}{49}+\dfrac{2}{50}\)
\(=2\left(\dfrac{1}{2}+\dfrac{1}{3}+\dfrac{1}{4}+...+\dfrac{1}{49}+\dfrac{1}{50}\right)\)
=>A/B=25
B= 99 - 98 + 97 -96 + 95 - 94+ ........+ 49 - 48 = ?
B = 99 - 33 + 97 - 96 + 95 - 94 +...+49 - 48
B = (99 - 33 ) + ((97 - 96 ) + ( 95 - 94 ) + ...+( 49 - 48 ))
B = 33 + 25
B = 58
Vậy B = 58
4 Thực hiện các phép tính :
a) 196 - ( 457 - 125 )
b) - 145 + [ 216 + ( - 314 ) ]
c) 88 - [ - 116 + 250 ]
d) - 47 + ( 252 - 315 )
k) ( - 496 - 125 ) + 718
4 Thực hiện các phép tính :
a) 196 - ( 457 - 125 )
= 196 - 332 = -136
b) - 145 + [ 216 + ( - 314 ) ]
= -145 + (-98) = - 243
c) 88 - [ - 116 + 250 ]
= 88 - 134 = 46
d) - 47 + ( 252 - 315 )
= -47 + (-63) = -110
k) ( - 496 - 125 ) + 718
= -621 + 718 = 97
Tíc nhA !
Tính nhanh: 47 x 98 + 94
Làm nhanh hộ mik nha! Mik đang cần gấp!!
47 x 98 + 94
= 47 x 98 + 47 x 2
= 47 x ( 98 + 2 )
= 47 x 100
= 4700
học tốt ^^
47 x 98 + 94
= 47 x 98 + 47 x 2
= 47 x (98 + 2)
= 47 x 100
= 4700