24 . 5 – 310 : 39
Tính : D=723 x 542 : 1084
E=310 x 11 x 5 : 39 x 24
723×542:1084=361.5
310×11×5:39×24=10492.30769
24 . 55 + 52. 53 =
7 . 39 + 310 + 51 . 38 =
( x - 3 )2 = ( x - 3 )3
10 - { [ ( x : 4 + 15 ) : 10 + 3 . 24 ] :10 } = 5
\(\left(x-3\right)^2=\left(x-3\right)^3\Leftrightarrow\left(x-3\right)^3-\left(x-3\right)^2=0\)
\(\Leftrightarrow\left(x-3\right)^2\left[x-3-1\right]=0\Leftrightarrow\left(x-3\right)^2\left(x-4\right)=0\Leftrightarrow x=3;x=4\)
\(10-\left\{\left[\left(x:4+15\right):10+3.2^4\right]:10\right\}=5\)
\(\Leftrightarrow\left[\left(\dfrac{x}{4}+15\right):10+3.16\right]:10=5\)
\(\Leftrightarrow\left(\dfrac{x}{4}+15\right):10+48=50\Leftrightarrow\left(\dfrac{x}{4}+15\right):10=2\Leftrightarrow\dfrac{x}{4}+15=20\)
\(\Leftrightarrow x=20\)
thực hiện phép tính
a, (35* 37) : 310+ 5 * 24- 73 : 7
b, (75+ 79)* (54+56)*((33*3-92)
a) (3⁵ . 3⁷) : 3¹⁰ + 5 . 2⁴ - 7³ : 7
= 3¹² : 3¹⁰ + 5.16 - 7²
= 3² + 80 - 49
= 9 + 31
= 40
b) (7⁵ + 7⁹) . (5⁴ + 5⁶) . (3³.3 - 9²)
= (7⁵ + 7⁹) . (5⁴ + 5⁶) . (81 - 81)
= (7⁵ + 7⁹) . (5⁴ + 5⁶) . 0
= 0
tính giá trị biểu thức
35+37+39+41+...+105
5-10+15-20+25-30+35+...+305-310+315
tìm x
D= 5+( 15-10)+(25-20)+...+(315-310)
giúp mình nha mai mình nộp mình tick cho
Tính nhanh
a) 75*2014+2015 *24+1990
B) 5+10+15+20+.............+300+305+310
a)75*2014+2015*24+1990=75*2015-75+2015*24+2015-25=2015*(75+24+1)-100=2015*100-100=201500-100=201400
b)Số các số hạng là:(310-5):5+1=62
Ta có:5+10+15+20+.......+300+305+310=(5+310)+(10+305)+...+(15+300)=315*62=19530
a) 25 - 53 : 52 + 12 : 22
b) 5 [ ( 85 - 35 : 7 ) : 8 + 90 ] - 50
c) 2. [ ( 7 - 33 : 32 ) 22 + 99 ] - 100
d) 27 : 22 + 54 : 53 . 24 - 3 . 25
e) ( 35 . 37 ) : 310 + 5 . 24 - 73 : 7
f) 32 . [ ( 52 - 3 ) : 11 ] - 24 + 2 . 103
g) ( 62007 - 62006 ) : 62006
h) ( 52001 - 52000 ) : 52000
i) ( 72005 + 72004 ) : 72004
j) ( 57 + 75 ) . ( 68 + 86 ) . ( 24 - 42 )
k) ( 57 + 79 ) . ( 54 + 56 ) . ( 33 . 3 - 92 )
l) [ ( 52 . 23) - 72 . 2 ) : 2 ] 6 - 7 . 25
a) 23 – 53 : 52 + 12.22 | b) 5[(85 – 35 : 7) : 8 + 90] – 50 |
c) 2.[(7 – 33 : 32) : 22 + 99] – 100 | d) 27 : 22 + 54 : 53 . 24 – 3.25 |
e) (35 . 37) : 310 + 5.24 – 73 : 7 | f) 32.[(52 – 3) : 11] – 24 + 2.103 |
g) (72005 + 72004) : 72004 | h) (57 + 75).(68 + 86).(24 – 42) |
i) (75 + 79).(54 + 56).(33.3 – 92) | j) [(52.23) – 72.2) : 2].6 – 7.25 |
a: \(2^3-5^3:5^2+12\cdot2^2\)
\(=8-5+48\)
\(=51\)
b: \(5\cdot\left[\left(85-35:7\right):8+90\right]-5\)
\(=5\cdot\left[10+90\right]-5\)
=495
A 2+22+....+219+220
B 2+22+....+299+2100
C 3+32+.....+39+310
a: 2A=2^2+2^3+...+2^21
=>A=2^21-2
b: B=2+2^2+...+2^100
=>2B=2^2+2^3+...+2^101
=>B=2^101-2
c: C=3+3^2+...+3^10
=>3C=3^2+3^3+...+3^11
=>2C=3^11-3
=>C=(3^11-3)/2
`A = 2 + 2^2 + ... + 2^20`
`=> 2A = 2^2 + 2^3 + ... +2^21`
`=> 2A-A = (2^2 + 2^3 + ... + 2^21) - (2 + 2^2 + ... +2^20)`
`=> A = 2^21 - 2`
`B = 2 + 2^2 + ... + 2^99 + 2^100`
`=>2B = 2^2 + 2^3 + ... + 2^100 + 2^101`
`=> 2B-B = (2^2 + 2^3 + ... + 2^101)- (2 + 2^2 + ... + 2^100)`
`=> B = 2^101 - 2`
`C = 3 + 3^2 + .... + 3^10`
`=>3C = 3^2 + 3^3 + ... +3^11`
`=>3C - C = (3^2 + 3^3 + ... +3^11) - (3 + 3^2 + .... + 3^10)`
`=> 2C = 3^11 - 3`
`=> C = (3^11 - 3)/2