2 x 8 + 72 =?
(2+4+6+8+10) x (72 x 8 x 8 x 8 )
Tính nhanh :
{ 2 + 4 + 6 + 8 + 10 } x { 72 x 8 x 8 x 8 }
{ 2 + 4 + 6 + 8 + 10 } x { 72 x 8 x 8 x 8 } = 30 x 36864 = 1105920
tính nhanh:(2+4+6+8+10) x (72 x 8 x 8 x 8 )
tìm x
a, [(6 * x - 72) : 2 - 84] * 28 +5628
b, 72 : {16 - [47 + (x - 2)]} =8
c, x + 132 + 128 + 124 + ...+ 76 + 72 + 68 = 2016
(các bạn giải rõ ra nhé)
a) 8 x 427 x 3 + 6 x 573 x 4
b) 6 x 1235 x 20 – 5 x 235 x 24
c) (72 x 135 + 9 x 65 + 8) : 25 – 3500 : 25
d) (18 x 957 – 9 x 354 x 2 – 3 x 621 x 6) : 72
a: =24*1000=24000
b: =120*1000=120000
c: =72(135+65):25-140
=72*8-140=436
d: =18(957-354-621):72=-9/2
tìm x : ( 72 × 72 + 72× 28 ) + x : 8
\(\left(72.72+72.28\right)+x:8\)
\(\left[72.\left(72+28\right)\right]+x:8\)
\(\left(72.100\right)+x:8\)
\(7200+x:8\)
\(x:8=-7200\)
\(x=-57600\)
vậy \(x=-57600\)
(x+2) ϵ B(8) và 18≤x≤72
x + 2 ∈ B(8) = {0; 8; 16; 24; 32; 40; 48; 56; 64; 72; 80; ...}
⇒ x ∈ {-2; 6; 14; 22; 30; 38; 46; 54; 62; 70; 78; ...}
Mà 18 ≤ x ≤ 72
⇒ x ∈ {22; 30; 38; 46; 54; 62; 70}
Tìm x :
a) ( 2.x - 40 ) : 10 = -55
b) (2.x + 15) : 5= -40
c) ( 2.x - 72) : 8 = 25
\(a,\left(2\times x-40\right):10=-55\)
\(2\times x-40=-55\times10\)
\(2\times x-40=-550\)
\(2\times x=-550+40\)
\(2\times x=-510\)
\(x=-510:2\)
\(\Rightarrow x=-255\)
\(b,\left(2\times x+15\right):5=-40\)
\(2\times x+15=-40\times5\)
\(2\times x+15=-200\)
\(2\times x=-200-15\)
\(2\times x=-215\)
\(x=-215:2\)
\(\Rightarrow x=-\dfrac{215}{2}\)
\(c,\left(2\times x-72\right):8=25\)
\(2\times x-72=25\times8\)
\(2\times x-72=200\)
\(2\times x=200+72\)
\(2\times x=272\)
\(x=272:2\)
\(\Rightarrow x=136\)
a. ( 2.x - 40 ) ÷ 10 = -55
2.x - 40 = (-55) × 10
2.x - 40 = -550
2.x = (-550) + 40
2.x = -510
x = (-510) ÷ 2
x = -255
b. ( 2.x + 15 ) ÷ 5 = -40
2.x + 15 = (-40) × 5
2.x + 15 = -200
2.x = (-200 ) - 15
2.x = -215
x = (-215) ÷ 2
x = -107,5
c. ( 2.x - 72 ) ÷ 8 = 25
2.x - 72 = 25 × 8
2.x - 72 = 200
2.x = 200 + 72
2.x = 272
x = 272 ÷ 2
x = 136
Tìm x biết: x × 8 + 72 = 72?
A. x = 0
B. x = 1
C. x = 2
D. x = 3