tim x biet
a) 4(x+1)^2-9(x+2)^2=0
b) 4(x+1)^2+(2x-1)^2-8(x+1)(x-1)=11
giai cach lam giup minh nha
Những câu hỏi liên quan
tim x biet :x+5-7+1+5+8-9-1+2+4+5.4-4<98
giai cach lam ra nha
làm nhanh tớ đang cần gấp
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1 tim x , biet
a) x - 7va 5/8 = 1 va 1/4
b) x + 7 va 5/8 = 9 va 1/4
c) ( x - 7 va 5/8 ) : 1/2 = 3
d) x / 1x3 + x/3x5+.....+x/97x99=99
giup mik nhanh nha . mik can gap lam
\(a,x-7\frac{5}{8}=1\frac{1}{4}\)
=> \(x-\frac{61}{8}=\frac{5}{4}\)
=> \(x=\frac{5}{4}+\frac{61}{8}\)
=> \(x=\frac{10}{8}+\frac{61}{8}=\frac{71}{8}=8\frac{7}{8}\)
\(b,x+7\frac{5}{8}=9\frac{1}{4}\)
=> \(x+\frac{43}{5}=\frac{37}{4}\)
=> \(x=\frac{37}{4}-\frac{43}{5}=\frac{13}{20}\)
\(c,\left[x-7\frac{5}{8}\right]:\frac{1}{2}=3\)
=> \(\left[x-\frac{61}{8}\right]=3\cdot\frac{1}{2}\)
=> \(\left[x-\frac{61}{8}\right]=\frac{3}{2}\)
=> \(x-\frac{61}{8}=\frac{3}{2}\)
=> \(x=\frac{3}{2}+\frac{61}{8}=\frac{12}{8}+\frac{61}{8}=\frac{73}{8}=9\frac{1}{8}\)
d, \(\frac{x}{1\cdot3}+\frac{x}{3\cdot5}+\frac{x}{5\cdot7}+...+\frac{x}{97\cdot99}=99\)
=> \(\frac{x}{2}\left[\frac{2}{1\cdot3}+\frac{2}{3\cdot5}+\frac{2}{5\cdot7}+...+\frac{2}{97\cdot99}\right]=99\)
=> \(\frac{x}{2}\left[1-\frac{1}{3}+\frac{1}{3}-\frac{1}{5}+...+\frac{1}{97}-\frac{1}{99}\right]=99\)
=> \(\frac{x}{2}\left[1-\frac{1}{99}\right]=99\)
=> \(\frac{x}{2}\cdot\frac{98}{99}=99\)
=> \(\frac{98x}{198}=99\)
=> 98x = 99 . 198
=> 98x = 19602
=> x = 19602 : 98 = 9801/49
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a) \(x-7\frac{5}{8}=1\frac{1}{4}\)
=> \(x=\frac{5}{4}+\frac{61}{8}\)
=> \(x=\frac{71}{8}\)
b) \(x+7\frac{5}{8}=9\frac{1}{4}\)
=> \(x=\frac{37}{4}-\frac{61}{8}\)
=> \(x=\frac{13}{8}\)
c) \(\left(x-7\frac{5}{8}\right):\frac{1}{2}=3\)
=> \(x-\frac{61}{8}=3.\frac{1}{2}\)
=> \(x-\frac{61}{8}=\frac{3}{2}\)
=> \(x=\frac{3}{2}+\frac{61}{8}\)
=> \(x=\frac{73}{8}\)
d) \(\frac{x}{1.3}+\frac{x}{3.5}+...+\frac{x}{97.99}=99\)
=> \(x.\frac{1}{2}.\left(\frac{2}{1.3}+\frac{2}{3.5}+...+\frac{2}{97.99}\right)=99\)
=> \(\frac{1}{2}x\left(1-\frac{1}{3}+\frac{1}{3}-\frac{1}{5}+....+\frac{1}{97}-\frac{1}{99}\right)=99\)
=> \(x\left(1-\frac{1}{99}\right)=99:\frac{1}{2}\)
=> \(x.\frac{98}{99}=198\)
=> \(x=198:\frac{98}{99}=\frac{9801}{49}\)
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\(b,\text{ }x+7\frac{5}{8}=9\frac{1}{4}\)
\(x=9\frac{1}{4}-\left(7+\frac{5}{8}\right)\)
\(x=9+\frac{1}{4}-7-\frac{5}{8}\)
\(x=\left(9-7\right)+\left(\frac{1}{4}-\frac{5}{8}\right)\)
\(x=2+-\frac{3}{8}\)
\(x=2\frac{-3}{8}\)
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Tim x , biet :
( x + 1 ) + (x + 4 ) + (x + 7 ) + ... + (x + 28 ) = 155
ghi cach giai giup minh nha . lam dung , minh tick cho
Tim x, biet:
a)(x-3)^3-(x-3)(x^2+3x+9)+9(x-1)^2=15
b)(x^2-2)^2+4(x-1)^2-4(x^2-2)(x-1)=0
Giup minh voi!
1.tim x,biet
A) |x-1|+|x-5|=4
B) x-2=5-7
C) |x|=4-5
D) |x|+(3-4)=8+(-6)
E) 2-4-|2x+1|=5
Giup mik nha mik cho 1 like )))♡
tim x biet N thuoc
a) 2-(x+3)=1+2+3+4+5+..............+99
b)(x+1)+(x+2)+(x+3)+(x+4)+...............+(x+100)=5750
giup mk nha cac ban , mk dang can gap lam
a) 2-(x+3) = 1+2+3+...+99
1+2+3+...+99 → có 99 số hạng
2-(x+3) = (1+99).99 : 2
2-(x+3) = 4950
x+3 = 2 + 4950
x+3 = 4952
x = 4952 - 3
x = 4949
b) (x+1)+(x+2)+...+(x+100) = 5750
→ có 100 cặp
(x+x+x+...+x) + ( 1+2+3+...+100 ) = 5750
=> 100x + 5050 = 5750
100x = 5750 - 5050
100x = 700
x = 700 : 100
x = 7
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0o0 Nguyễn Đoàn Tuyết Vy 0o0 bà kêu tui học tốt có nghĩa là học giốt đúng ko
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b)(x+1)+(x+2)+(x+3)+(x+4)+...............+(x+100)=5750
(x+x+x+x+...+x) + (1+2+3+4+...+100) = 5750
100x + 5050 = 5750
100x = 5750 - 5050
100x = 700
x = 700 : 100
x = 7
Vậy ...
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Tim x biet:
(2x-1)5=(2x-1)7
Tim cac so nguyen to x , y thoa man:
(x-2)2.(y-3)2=4
trinh bay cach lam nhe
(2x-1)5=(2x-1)7
=>x=0;1;\(\frac{1}{2}\)
(x-2)2.(y-3)2=4
phân tích rồi kẻ bảng ra
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Rut gon a biet a=(x^2-2x/2^2+8+2x^2/8-4x+2x^2-x^3)x(1-1/-2/^2)
Ai giup minh minh tick nha ::)))
1. tinh :
a) 15/8 + 3/4 - 5/12
b) 11/24 x 12/33 + 5/6
c) 15/8 + 7/24 : 5/8
2 . tim x, biet :
a) x + 5/8 : 3/4 = 17/9
b) x - 5/9 x 18/15 = 1/3
c) x x7/8 - 5/8 = 13/24
d) X x1/7 + X x 1/4 + X x 1/4 =18
giup mik nhanh nha. mik can gap lam
a)15/8+3/4-5/12
=45+18-10/24
=53/24
b)11/24.12/33+5/6
=11.12/12.2.11.3+5/6
=1/6+5/6
=6/6=1
c)15/8+7/24:5/8
=15/8+7/24.8/5
=15/8+7.8/3.8.5
=15/8+7/15
=đề sai, nếu đúng thì như này
=8/15+7/15
=15/15=1
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