Tính nhanh: 500 x 4 x 2 x 25 - 500 x 3 x 2 x 30
500 x 30 x 25 x 75 x 95 x 110 = ?
Ai nhanh nhất mình tick
500 x 30 x 25 x 75 x 95 x 100 = 267187500000
500 x 30 x 25 x 75 x 95 x 110 = 293906250000
500 x 6 + 500 x 4 - 108 :12 : 9
9782 x 35 - 9782 x 25 + 1000 : 5 :2
37800 : 25 : 4 + 57 + 467 x 43
500x6+500x4-108:12:9
=500x(6+4)-9:9
=500x10-1
=5000-1
=4999
9782x35-9782x25+1000:5:2
=9782x(35-25)+200:2
=9782x10+100
=97820+100
=97920
37800:25:4+57+467x43
=1512:4+57+20081
=378+57+20081
=435+20081
=20516
4 x 25 - 12 x 5 + 170 : 10
( 7 + 3 mũ 3 : 3 mũ 2 ) x 4 - 3
12 : {400 :[ 500 - ( 125 + 25 x 7 )]}
168 + { [ 2 x (2 mũ 4 + 3 mũ 2 ) - 256 mũ 0 ] : 7 mũ 2
a) 4.25-12.5+170:10
=100-60+17
=40+17
=57
b) (7+33:32).4-3
=(7+3).4-3
=10.4-3
=40-3
=37
c) 12:{400:[500-(125+25.7)]}
=12:{400:[500-(125+175)]}
=12:{400:[500-300]}
=12:{400:200}
=12:2
=6
d) 168+{[2.(24+32)-2560]:72}
=168+{[2.(16+9)-1]:49}
=168+{[2.25-1]:49}
=168+{[50-1]:49}
=168+{49:49}
=168+1
=169
Tính?
a) 24 x 30 36 x 40 72 x 60 89 x 50
Mẫu: 24 x 30 = (24 x 3) x 10 = 720
b) 130 x 20 450 x 70 2 300 x 500 17 000 x 30
Mẫu: 130 x 20 = (13 x 2) x 100 = 2 600
a,
36 x 40 = (36 x 4) x 10 = 144 x 10 = 1 440
72 x 60 = (72 x 6) x 10 = 432 x 10 = 4 320
89 x 50 = (89 x 5) x 10 = 445 x 10 = 4 450
b,
450 x 70 = (45 x 7) x 100 = 315 x 100 = 31 500
2300 x 500 = (23 x 5) x 10 000 = 115 x 10 000 = 1 150 000
17 000 x 30 = (17 x 3) x 10 000 = 510 000
1. Tính nhanh.
1,3 x 2994 x 3 + 0,65 x 986 x 6 -1,3 x 5940
(30,5 - 15,5) x 70 + 30 x (30,5-15,5) -500
TÌM X
(x+1)+(x+2)+(X+3)+...+(x+30)=500
\(\left(x+1\right)+\left(x+2\right)+\left(x+3\right)+...+\left(x+30\right)=500\)
Số lượng số hạng là: \(30-1+1=30\)
\(\Rightarrow30x+\dfrac{30\left(30+1\right)}{2}=500\)
\(30x+465=500\)
\(30x=35\)
\(x=\dfrac{7}{6}\)
\(\left(x+1\right)+\left(x+2\right)+...+\left(x+30\right)=500\)
\(\Rightarrow x+1+x+2+..+x+30=500\)
\(\Rightarrow\left(x+x+...+x\right)+\left(1+2+...+30\right)=500\)
\(\Rightarrow30\cdot x+465=500\)
\(\Rightarrow30\cdot x=500-465\)
\(\Rightarrow30\cdot x=35\)
\(\Rightarrow x=\dfrac{35}{30}\)
\(\Rightarrow x=\dfrac{7}{6}\)
tính nhẩm phải nhanh
a) 50 x 2 x 8 - 6400 : 8
b) 12 x 2 x 500 +7600 :6
c) 5000 : 5 x 12 + 2 x 500
Tìm số tự nhiên x biết:
a) (3x - 17) . 42 = 43
b) 5x - 18 = -3
c) x chia hết cho 12; x chia hết cho 25; x chia hết cho 30 và 0 < x< 500.
\(a,\left(3x-17\right)4^2=4^3\)
\(3x-17=4\)
\(3x=21\)
\(x=7\)
\(b,5x-18=-3\)
\(5x=15\)
\(x=3\)
\(c,\hept{\begin{cases}x⋮12\\x⋮25\\x⋮30\end{cases}}\)\(\Rightarrow x\in B\left(12;25;30\right)\)
rồi tìm , lâu , quên =>> tìm BC xog thì xét ĐK rồi KL
\(\text{a) (3x - 17) . 4^2= 4^3}\)
\(\Rightarrow3x-17=4^3:4^2=4\)
\(\Rightarrow3x=4+17=21\)
\(\Rightarrow x=7\)
\(\text{b) 5x - 18 = -3}\)
\(\Rightarrow5x=-3+18=15\)
\(\Rightarrow x=15:5=3\)
c) x chia hết cho 12; x chia hết cho 25; x chia hết cho 30 và 0 < x< 500.
\(\Rightarrow x⋮12,x⋮25,x⋮30\)
\(\Rightarrow x\in BC\left(12,15,30\right)=30\)
\(\Rightarrow x\in\left\{0,30,60,90,120,150,...,480,....\right\}\)
Mà 0<x<500
\(\Rightarrow x\in\left\{30,60,90,120,150,...,480\right\}\)
học tốt
t.i.k nha
a) ( 3. x - 17 ) . 42 = 43
<=> 3.x - 17 = 43 :42
<=> 3.x - 17 = 4
<=> 3.x = 4 + 17
<=> 3.x = 21
<=> x = 21 : 7
<=> x = 3
Vậy x 3
b) 5.x - 18 = -3
<=> 5.x = (-3) + 18
<=> 5.x = 15
<=> x = 15 : 5
<=> x = 3
Vậy x = 3
c) Ta có : \(\hept{\begin{cases}x⋮12\\x⋮25\\x⋮30\end{cases}\Rightarrow x\in BC\left(12;25;30\right)}\)
Mà \(\hept{\begin{cases}12=2^2.3\\25=5^2\\30=2.3.5\end{cases}\Rightarrow BCNN\left(12,25,30\right)=300}\)
=> BC(12,25,30)=B(300 ) = { 0;300; 600 ;900 ;1200 ;... }
Mà 0< x < 500 = > x = 300
Vậy x = 300
x ⋮ 12 ; x ⋮ 25 ; x ⋮ 30 và 0 $\leq$ x $\leq$ 500
\(BCNN\left(12;25;30\right)=300\)
\(\Rightarrow x=300\) ( t/m điều kiện )
`=> x in BC(12, 25, 30)`.
Ta có: `12 = 2^2 xx 3`.
`25 = 5^2`.
`30 = 5 xx 2 xx 3`.
`=> x in B(300)`.
`=> x in {0, 300, 600, ...}` mà `0 <= x <= 500`
`=> x = 0, 300`.
`=>` Ta có:
`BCNNN (12; 25; 30) = 300`
`=>` `x = 300` vì:
`0 <= x <= 500`