7x-x=521:5193.22-70
x=?
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
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
a) 5x + x = 39 – 311:39 b) 2x : 25 = 16
| c) 7x – x = 521 : 519 + 3.22 - 70 d) 7x – 2x = 617: 615 + 44 : 11 |
a) \(5x+x=39-3^{11}:3^9\)
\(\Leftrightarrow6x=39-3^2\)
\(\Leftrightarrow6x=30\)
\(\Leftrightarrow x=5\)
b) \(2^x:2^5=16\)
\(\Leftrightarrow2^x:2^5=2^4\)
\(\Leftrightarrow2^x=2^4.2^5\)
\(\Leftrightarrow2^x=2^9\)
\(\Leftrightarrow x=9\)
c) \(7x-x=5^{21}:5^{19}+3.2^2-7^0\)
\(\Leftrightarrow6x=5^2+3.4-1\)
\(\Leftrightarrow6x=36\)
\(\Leftrightarrow x=6\)
d) \(7x-2x=6^{17}:6^{15}+44:11\)
\(\Leftrightarrow5x=6^2+4\)
\(\Leftrightarrow5x=40\)
\(\Leftrightarrow x=8\)
a)⇔6x=39-32
⇔6x=30
⇔ x=5
b)2x:25=16
⇔2x=24.25
⇔ 2x=29
⇔ x=9
c)⇔6x=52+3.22-1
⇔ 6x= 36
⇔ x=6
d)⇔5x=62+4
⇔ 5x=40
⇔ x=8
a) 5x + 3x = 36 : 33.4 + 12
4x + 2x = 68 – 219 : 216
a) 5x + x = 39 – 311:39
b) 7x – x = 521 : 519 + 3.22 - 70
c) 7x – 2x = 617: 615 + 44 : 11
a: \(\Leftrightarrow6x=30\)
hay x=5
b: \(\Leftrightarrow6x=25+12-1=36\)
hay x=6
a) 5x + 3x = 36 : 33.4 + 12
4x + 2x = 68 – 219 : 216
a) 5x + x = 39 – 311:39
b) 7x – x = 521 : 519 + 3.22 - 70
c) 7x – 2x = 617: 615 + 44 : 11
a: \(\Leftrightarrow8x=108+12=120\)
hay x=15
b: \(\Leftrightarrow6x=60\)
hay x=10
a) 5x + 3x = 120
x . (5+3)= 120
x . 8 = 120
x = 120 : 8
x = 15
c) 7x - 2x = 40
x .(7-2)= 40
x . 5 = 40
x = 40 : 5
x = 8
Bài 27. Tìm x biết
a. 89 – (73 – x) = 20 b. (x + 7) – 25 = 13 c. 98 – (x + 4) = 20
d. 140 : (x – 8) = 7 e. 4(x + 41) = 400 f. x – [ 42 + (–28)] = –8
g. x + 5 = 20 – (12 – 7) h. (x – 11) = 2.2³ + 20 : 5 i. 4(x – 3) = 7² – 1³.
j. 2x+1.22014 = 22015. k. 2x – 49 = 5.3² ℓ. 3²(x + 14) – 5² = 5.2²
m. 6x + x = 511 : 59 + 31. n. 7x – x = 521 : 519 + 3.2² – 70.
o. 7x – 2x = 617 : 615 + 44 : 11. p. 3x = 9 q. 4x = 64
r. 9x–1 = 9 s. x4 = 16 t. 2x : 25 = 1
u. |x – 2| = 0 v. |x – 5| = 7 – (–3) w. |x – 5| = |–7|
x. |x| – 5 = 3 y. 15 – 2|x| = 13
a) 89-(73-x) = 20
=> 73+x =89-20
=> 73+x=69
=> x=69-73
=> x=-4
b) (x+7)-25=13
=> x+7=13+25
=> x+7=38
=> x=38-7
=> x=31
c) 98-(x+4)=20
=> x+4=98-20
=> x+4=78
=> x=78-4
=> x=73
d) 140:(x-8)=7
=> x-8=140:7
=> x-8=20
=> x=20+8
=> x=28
e) 4(x+41)=400
=> x+41=400:4
=> x+41=100
=> x=100-41
=> x=59
f) x-[42+(-28)]=-8
=> x-14=-8
=> x=-8+14
=> x=6
g) x+5=20-(12-7)
=> x+5=20-5
=> x+5=15
=> x=15-5
=> x=10
h) \(x-11=2.2^3+20:5\)
=> x-11=2.8+4
=> x-11=16+4
=> x-11=20
=> x=20+11
=> x=31
i) \(4\left(x-3\right)=7^2-1^3\)
=> 4(x-3)=49-1
=> 4(x-3)=48
=> x-3=48:4
=> x-3=12
=> x=12+3
=> x=15
(7x-84):2- 70=210 với X/N
(7x - 84) : 2 - 70 = 210
(7x - 84) : 2 = 210 + 70
(7x-84) : 2 = 280
7x - 84 = 280 x 2
7x - 84 = 560
7x = 560 + 84
7x = 644
x = 644: 7
x = 92
Tìm x, biết:
x . − 3 7 = 5 21
Tính x:
a, (-70).(2x - 15) - 12 . (11-7x) = 100
b, 41 . (2 - 7x) - 15. ( x - 4) = 20
c, 11. (15x - 6 ) + 4 .(3x - 8) = 15
d, 2 . ( 70 - 8x ) - 11 ( 7 - 2x ) = 19
Giúp mình với , mai mình phải nộp rồi.
Các bn giúp mình nhanh đk ko. Cảm ơn các bạn nhiều nha.
a: =>-140x+1050-132+84x=100
=>-56x=100+132-1050=-818
=>x=409/28
b: \(\Leftrightarrow82-287x-15x+60=20\)
=>-302x+142=20
=>-302x=-122
=>x=61/151
c: =>165x-66+12x-32=15
=>177x=113
=>x=113/177
d: =>140-16x-77+22x=19
=>6x+63=19
=>6x=-44
=>x=-22/3
5 (x+7)-10 =50
42 :x-5 =1
(x-1)(x-4) =5
7x+8x-5x = 70
4x+ 9 x - x = 60
1) 5 ( x + 7 ) - 10 = 50 => 5 ( x + 7 ) = 60
=> x + 7 =12
=> x = 12 - 7
=> x = 5
2) 42 : x - 5 = 1
=> 42 : x = 6
=> x = 7
3) ( x-1 ) ( x- 4 ) = 5
=> x = - 0,1925.....
4) 7x + 8x - 5x = 70
=> 10x = 70
=> x = 7
5) 4x + 9x - x = 60
=> 12x = 60
=> x = 5
*)5(x+7)-10=50
5(x+7)=60
x+7=12
x=5
*)42:x-5=1
42:x=6
x=7
*)7x+8-5x=70
x(7+8-5)=70
10x=70
x=7
*)4x+9x-x=60
x(4+9-1)=60
12x=60
x=5