3.22 nha :)))
7x - x = 521: 519 + 3.22 - 7
7x - x = 30
7.x - 1.x = 30
x . (7-1) = 30
x . 6 = 30
x = 30 : 6
x = 5
DỄ ƠI LÀ DỄ
3^3.22-3^3.19 = ?
=\(3^3\left(22-19\right)\)
=\(3^3.3\)
=\(3^4\)=81
3^3.22-3^3.19
= 33 ( 22-19 )
= 33 . 3
= 81
{210:[16+3.(6+3.22)]}–3
\(\left\{210:\left[16+3.\left(6+3.22\right)\right]\right\}-3\)
\(=\left\{210:\left[16+3.\left(6+66\right)\right]\right\}-3\)
\(=\left\{210:\left[16+3.72\right]\right\}-3\)
\(=\left\{210:\left[16+216\right]\right\}-3\)
\(=\left\{210:232\right\}-3\)
\(=\dfrac{105}{116}-3\)
\(=\dfrac{-243}{116}\)
7x - x = 521 : 519 + 3.22 - 7 0
\(7x-x=5^{21}:5^{19}+3.2^2-7^0\)
\(6x=5^2+3.2-1\)
\(6x=25+12-1\)
\(6x=36\)
\(x=6\)
K bt đk:))
Ta có :
7x - x = 521 : 519 . 3 . 22 - 70
=> 6x = 521: 519 + 3 . 22 - 70
=> 6x = 52 + 3. 4 - 1
=> 6x = 25 + 3 . 2 - 1
=> 6x = 25 + 6 - 1
=> 6x = 30
=> x = 30 : 6
=> x = 5
7x−x=521:519+3.22−70
6x=52+3.2−16x=52+3.2−1
6x=25+12−16x=25+12−1
6x=366x=36
x=6
Tính tổng S = 1 + 2.2 + 3.2 2 + 4.2 3 + ... + 2018.2 2017 .
A. S = 2017.2 2018 + 1.
B. S = 2017.2 2018 .
C. S = 2018.2 2018 + 1.
D. S = 2019.2 2018 + 1.
Đáp án A
y = x + x 2 + x 3 + ... + x 2018 = x 1 − x 2018 1 − x y ' = 1 + 2 x + 3 x 2 + ... + 2018 x 2017 = 2018 x 2019 − 2019 x 2018 + 1 ( 1 − x ) 2 y ' ( 2 ) = 1 + 2.2 + 3.2 2 + ... + 2018.2 2017 = 2017.2 2018 + 1
Tính tổng S = 1 + 2 . 2 + 3 . 2 2 + 4 . 2 3 + . . . + 2018 . 2 2017
Tính tổng S = 1 + 2 . 2 + 3 . 2 2 + 4 . 2 3 + . . . + 2018 . 2 2017
A. S = 2017 . 2 2018 + 1
B. S = 2017 . 2 2018
C. S = 2018 . 2 2018 + 1
D. S = 2019 . 2 2018 + 1
Tính tổng S = 1 + 2.2 + 3.2 2 + 4.2 3 + ... + 2018.2 2017
A. S = 2018.2 2017 + 1
B. S = 2017.2 2018 .
C. S = 2018.2 2018 .
D. S = 2019.2 2018 + 1.
Tính tổng S = 1 + 2 . 2 + 3 . 2 2 + 4 . 2 3 + . . . + 2018 . 2 2017
A. S = 2017 . 2 2018 + 1
B. S = 2017 . 2 2018
C. S = 2018 . 2 2018
D. S = 2019 . 2 2018 + 1