Tình nhanh
625:(35x7-120)
600:(20x6+30)
5x(180-75x2)
125-(315-53x5)
[(5x30+15)-65]:2
[3x[40+15x4)-178]-24
{121-[(24x6+6x76):100+15]}:4+35
{[(175-25x3):25+6]+120}:4+34
128-{[315-(42+58)]:5+57}
[(8x50-356)x3-44]+56
Mong mọi người giúp em
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20+21+22+23+24+25+26+27+28+29+30+31+32+33+34+35+36+37+38+39+40+41+42+43+44+45+46+47+48+49+50+51+52+53+54+56+57+58+59+60+61+62+63+64+65+66+67+68+69+70=?
x+5.2-(32+16.3;16-15)=0
2448;[119-(x-6)=24
20-[7.(x-3)+4]=2
x;[(1800+600);30]=560;(315-35)
[(1250-25);15];x=(450-60);130
Bài 4 : Tính nhanh :
a: 53 x 39 + 47 x 39 - 53 x 21 - 47 x 21
b: 2 x 53 x 12 + 4 x 6 x 87 - 3 x 8 x 40
c: 5 x 7 x 77 - 7 x 60 + 49 x 25 - 15 x 42
Bài 5 : Tìm x , biết :
a: x : [( 1800 + 600 ) : 30 ] = 560 : ( 315 - 35 )
b: [( 250 - 25 ) : 15 ] : x = ( 450 - 60 ) : 130
Bạn dùng tính chất phân phối, giao hoán để làm nhé
1) a) 53 x 39 + 47 x 39 - 53 x 21 - 47 x 21
= 39 x (53 + 47) - 21 x (53 - 47)
= 39 x 100 - 21 x 6
= 3900 - 126
= 3774
b) 2 x 53 x 12 + 4 x 6 x 87 - 3 x 8 x 40
= 1272 + 2088 - 960
= 3360 - 960
= 2400
c) 5 x 7 x 77 - 7 x 60 + 47 x 25 - 15 x 42
= 2695 - 420 + 1175 - 630
= 2275 + 545
= 2820
2) a) x : [(1800 + 600) : 30] = 560 : (315 - 35)
x : (2400 : 30) = 560 : 280
x : 80 = 2
x = 2 x 80
=> x = 160
b) [(250 - 25) : 15] : x = (450 - 60) : 130
225 : 15 : x = 390 : 130
15 : x = 3
x = 15 : 3
=> x = 5
Học tốt!!!
Tìm x biết:
X*99+x=100
420+65*x=(x+175):5+30
x:[(1800+600):30]=5600:(315-35)
a)\(x.99+x=100\)
\(\Rightarrow x.\left(99+1\right)=100\)
\(\Rightarrow x.100=100\)
\(\Rightarrow x=1\)
b)\(420+65.x=\left(x+175\right):5+30\)
\(420+65.x=\left(x+175\right).\dfrac{1}{5}+30\)
\(420+65.x=\dfrac{1}{5}x+35+30=\dfrac{1}{5}x+65\)
\(\Rightarrow420-65=\dfrac{1}{5}x-65x\)
\(\Rightarrow-64,8x=355\)
\(\Rightarrow x=-\dfrac{1775}{324}\)
c)\(x:\left[\left(1800+600\right):30\right]=5600:\left(315-35\right)\)
\(x:80=20\Rightarrow x=20.80=1600\)
Tìm số tự nhiên x biết:
a) x : 1800 + 600 : 30 = 560 : 315 - 35
b) 250 - 25 : 15 : x = 450 - 60 : 130
c) 6 x - 72 : 2 - 84 . 28 = 5628
d) 5 x + x - 6 = 12
Tìm số tự nhiên x biết:
a) x : [(1800 + 600):30] = 560 : (315 – 35)
b) [(250 – 25):15] : x = (450 – 60) : 130
c) [(6x – 72) : 2 – 84].28 = 5628
d) 5x + x – 6 = 12
1 * 2 * 3 * 4 * 5 * 6 * 7 * 8 * 9 * 10 * 11 * 12 * 13 * 14 * 15 * 16 * 17 * 18 * 19 * 20 * 21 * 22 * 23 * 24 * 25 * 26 * 27 * 28 * 29 * 30 * 31 * 32 * 33 * 34 * 35 * 36 * 37 * 38 * 39 * 40 * 41 * 42 * 43 * 44 * 45 * 46 * 47 * 48 * 49 * 50 * 51 * 52 * 53 * 54 * 55 * 56 * 57 * 58 * 59 * 60 * 61 * 62 * 63 * 64 * 65 * 66 * 67 * 68 * 69 * 70 * 71 * 72 * 73 * 74 * 75 * 76 * 77 * 78 * 79 * 80 * 81 * 82 * 83 * 84 * 85 * 86 * 87 * 88 * 89 * 90 * 91 * 92 * 93 * 94 * 95 * 96 * 97 * 98 * 99 * 100 bằng bao nhiêu?
a) x-280;35=5.54
b) (x-280);35=56;5
c)x;15+42=13+25.8
d) (x-128+20);192=0
e) 460+85.4=(x+200).4
g) x+5.2-(32+16.3;16-15)=0
h) 2448;[119-(x-6)]=24
i) 20-[7.(x-3)+4]=2
k) x;[(1800+600);30]=560;(315-35)
l) [(1250-25);15];x=(450-60);130
Ai giải nhanh nhất mình tick cho