Câu hỏi : Tìm x
a, (19x+2.5 mũ 2):14 = ( 13 - 8) mũ 2 - 4 mũ 2
b, x + ( x + 1 ) + ( x + 2 ) +...+ ( x + 30 )= 1240
c, 11- ( -53 + x ) = 97
d,-(x + 81) + 213 = -16
Những câu hỏi liên quan
Tìm x bt:
a, 3/7-1/7.x=2/3
b, 3x mũ 2-2=72
c, (19x+2.5 mũ 2):14=(13-8) mũ 2-4 mũ 2
d, x:1/2+x:1/4+x:1/8+x:1/16+x:1/32=343
a) \(\frac{3}{7}-\frac{1}{7}x=\frac{2}{3}\)
=> \(\frac{1}{7}x=\frac{3}{7}-\frac{2}{3}=-\frac{5}{21}\)
=> \(x=-\frac{5}{21}:\frac{1}{7}=-\frac{5}{21}\cdot7=-\frac{5}{3}\)
b) \(3x^2-2=72\)=> 3x2 = 74 => x2 = 74/3 => x không thỏa mãn
c) \(\left(19x+2\cdot5^2\right):14=\left(13-8\right)^2-4^2\)
=> \(\left(19x+2\cdot25\right):14=5^2-4^2=9\)
=> \(\left(19x+50\right):14=9\)
=> \(19x+50=126\)
=> \(19x=76\)
=> x = 4
d) \(x:\frac{1}{2}+x:\frac{1}{4}+x:\frac{1}{8}+x:\frac{1}{16}+x:\frac{1}{32}=343\)
=> \(x\cdot2+x\cdot4+x\cdot8+x\cdot16+x\cdot32=343\)
=> \(x\left(2+4+8+16+32\right)=343\)
=> x . 62 = 343
=> x = 343/62
7236 nhan 3 thì bang may
a) (19x+2.5^2):14=(13-8)^2-4^2
b) x+(x+1)+(x+2)+...+(x+30)=1240
c) 11-(-53+x)=97
d) -(x+84)+213=-16
(3.4.2^16)^2/11.2^13.4^11-16^9.Tính bằng cách hợp lý
Câu 2:
a,(19x+2.5^2):14=(13-8)^2-4^2
b,x+(x+1)+(x+2)+...+(x+30)=1204
c,11-(-53+x)=97
d,-(x+84)+213=-16
text{Tìm x, biết:}a) left(19x+2.5^2right):14left(13-8right)^2-4^2b) x+left(x+1right)+left(x+2right)+...+left(x+30right)1240c) 11-left(-53+xright)97d) -left(x+84right)+213-16
Đọc tiếp
\(\text{Tìm x, biết:}\)
\(a\)) \(\left(19x+2.5^2\right):14=\left(13-8\right)^2-4^2\)
\(b\)) \(x+\left(x+1\right)+\left(x+2\right)+...+\left(x+30\right)=1240\)
\(c\)) \(11-\left(-53+x\right)=97\)
\(d\)) \(-\left(x+84\right)+213=-16\)
tim x
3 mũ x-2.9=81
(19x+2,5 mũ 2) :14=(13-8)mũ 2-4 mũ 2
3^x-2.9=81
3^x-2=81:9
3^x-2=9
3^x=9+2
3^x=11
3^x= tap hop rong
Suy ra x = tap hop rong
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Bài 2: Tìm số tự nhiên x,biết:
1, 2 mũ x 4
2, 2 mũ x 8
3, 2 mũ x 16
4, 2 mũ x 1
5, 3 mũ x 9
6, 3 mũ x 81
7, 3 mũ x 27
8, 5 mũ x 25
9, 5 mũ x 125
10, 8 mũ x 64
11, 3 mũ x + 1 3 mũ 2
12, 2 mũ 2 x + 1 2 mũ 7
13, 5 mũ x - 1 5 mũ 2
14, 5 mũ 2 x - 4 5 mũ 10
15, 6 x + 4 6 mũ 10
16, 2 mũ 2 x - 3 2 mũ 9
17, 7 mũ 2 x - 3 7 mũ 7
18, 8 mũ x - 2 1
19, 9 mũ x - 8 81
20, 10 mũ 2 x - 1 1000
Giúp mình với,mình đang cần gấp !!
Đọc tiếp
Bài 2: Tìm số tự nhiên x,biết:
1, 2 mũ x = 4
2, 2 mũ x = 8
3, 2 mũ x = 16
4, 2 mũ x = 1
5, 3 mũ x = 9
6, 3 mũ x = 81
7, 3 mũ x = 27
8, 5 mũ x = 25
9, 5 mũ x = 125
10, 8 mũ x = 64
11, 3 mũ x + 1 = 3 mũ 2
12, 2 mũ 2 x + 1 = 2 mũ 7
13, 5 mũ x - 1 = 5 mũ 2
14, 5 mũ 2 x - 4 = 5 mũ 10
15, 6 x + 4 = 6 mũ 10
16, 2 mũ 2 x - 3 = 2 mũ 9
17, 7 mũ 2 x - 3 = 7 mũ 7
18, 8 mũ x - 2 = 1
19, 9 mũ x - 8 = 81
20, 10 mũ 2 x - 1 = 1000
Giúp mình với,mình đang cần gấp !!
Tìm x,biết :
a)\(\left(19x+2.5^2\right):14=\left(13-8\right)^2-4^2\)
b)x+(x+1)+(x+2)+...+(x+30)=1240
c)11-(-53+x)=97
d)-(x+84)+213=-16
a) \(\left(19x+2\cdot5^2\right):14=\left(13-8\right)^2-4^2\)
\(\Leftrightarrow\left(19x+2\cdot25\right):14=5^2-4^2\)
\(\Leftrightarrow19x+50=\left(25-16\right)\cdot14\)
\(\Leftrightarrow19x+50=9\cdot14\)
\(\Leftrightarrow19x+50=126-50\)
\(\Leftrightarrow19x=76\)
\(\Leftrightarrow x=76:19\)
\(\Leftrightarrow x=4\)
b) \(x+\left(x+1\right)+\left(x+2\right)+...+\left(x+30\right)=1240\)
\(\Leftrightarrow\left(x+x+x+x...+x\right)+\left(1+2+3+...+30\right)=1240\)
\(\Leftrightarrow31x+\frac{\left[\left(30-1\right):1+1\right]\cdot\left(30+1\right)}{2}=1240\)
\(\Leftrightarrow31x+465=1240\)
\(\Leftrightarrow31x=775\)
\(\Leftrightarrow x=25\)
c)\(11-\left(-53+x\right)=97\)
\(\Leftrightarrow-53+x=-86\)
\(\Leftrightarrow x=-33\)
d) \(-\left(x+84\right)+213=-16\)
\(\Leftrightarrow-\left(x+84\right)=-229\)
\(\Leftrightarrow x+84=229\)
\(\Leftrightarrow x=145\)
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tìm x biết:
a,125:5 mũ 2 .[x-3]=3
b, [2x-5] mũ 3 = 27
c,[19.x+2.5 mũ 2] :14 =[13-8]mũ 2 - 4 mũ 2
125 : 5^2 . (x-3) = 3
125 : 25 .(x-3) = 3
5 (x-3) =3
x-3 = 3 : 5
Đề bài sai hay sao ý?
2x -5 = 3
2x = 3+5 =8
x =4
(19 .x+2.5^2 ): 14 = (13-8)^2 - 4^2
19x + 50) : 14 = 25 - 16
(19x+50) : 14 = 9
19x+50 = 3*14 = 126
19x = 126-50 = 76
x = 76 / 19 = 4
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\(a\)) \(125:5^2.\left(x-3\right)=3\)
\(5^3:5^2.\left(x-3\right)=3\)
\(5.\left(x-3\right)=3\)
\(5x-15=3\)
\(5x=3+15\)
\(5x=18\)
\(x=\frac{18}{5}\)\(.\)Vậy \(x=\frac{18}{5}\)
\(b\)) \(\left(2x-5\right)^3=27\)
\(\left(2x-5\right)^3=3^3\)
\(\Rightarrow2x-5=3\)
\(\Rightarrow2x=8\)
\(\Rightarrow x=4\)\(.\)Vậy \(x=4\)
\(c\))\(\left(19.x+2.5^2\right):14=\left(13-8\right)^2-4^2\)
\(\left(19.x+2.25\right):14=5^2-16\)
\(\left(19.x+2.25\right):14=25-16\)
\(\left(19.x+50\right):14=9\)
\(19.x+50=126\)
\(19.x=126-50\)
\(19.x=76\)
\(x=76:19\)
\(x=4\)\(.\)Vậy \(x=4\)
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tìm x
a) 2 . 3 mũ x = 10 . 3 mũ 12 + 8 . 27 mũ 4
b ) ( 19x + 2 . 5 mũ 2 ): 14 = ( 13 - 8 ) mũ 2 - 4 mũ 2
2.3x= 10.312+8.274
2.3x = 10.(33)4+ (33)4 . 8
2.3x= (33)4. 18
2.3x= (33)4.2.32
2.3x= 312+2.2
2.3x= 314.2
=> x = 14
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