tim x, y biet
x/49=-3/7
b, x-2/12=2/3
c,x-1/9=x+3=15
d,3/x=9/35=-36/84
Những câu hỏi liên quan
a) 42-x=5
b) 15.(x+4)=75
c) 27+3x=9^8.9^7
d) x+18=12
e) 2x-15=-19
f) 36 :(x^3-12)=-3
g)x+15=35
h) 2x-13=3^2
a) 42 - x = 5
x = 42 - 5
x = 37
b) 15.(x + 4) = 75
x + 4 = 75 : 15
x + 4 = 5
x = 5 - 4
x = 1
d) x + 18 = 12
x = 12 - 18
x = -6
e) 2x - 15 = -19
2x = (-19) + 15
2x = -4
x = -4 : 2
x = -2
f) 36 : (x^3 - 12) = -3
x^3 - 12 = 36 : (-3)
x^3 - 12 = -12
x^3 = 0
=> x = 0
g)x + 15 = 35
x = 35 - 15
x = 20
h) 2x - 13 = 3^2
2x - 13 = 9
2x = 9 + 13
2x = 22
x = 22 : 2
x = 11
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a) 42-x=5
x=42-5
x= 37
b)15*(x+4)=75
x+4=75:15
x+4=5
x =5-4
x = 1
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a) 42 - x = 5
x = 42 - 5
x = 37
b) 15.(x + 4) = 75
x + 4 = 75 : 15
x + 4 = 5
x = 5 - 4
x = 1
d) x + 18 = 12
x = 12 - 18
x = -6
e) 2x - 15 = -19
2x = (-19) + 15
2x = -4
x = -4 : 2
x = -2
f) 36 : (x^3 - 12) = -3
x^3 - 12 = 36 : (-3)
x^3 - 12 = -12
x^3 = 0
=> x = 0
g)x + 15 = 35
x = 35 - 15
x = 20
h) 2x - 13 = 3^2
2x - 13 = 9
2x = 9 + 13
2x = 22
x = 22 : 2
x = 11
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Tính hợp lí nếu có thể:
a)3/7+4/9+4/7+5/9
b)1/5+4/10+9/15+16/20+25/25+36/30+49/35+64/40+81/45
c)1/8+1/12+3/8+5/12
d)(1-1/2)x(1-1/3)x(1-1/4)x...x(1-100)
e)9/5:17/15+8/5:17/15
f)2/1x2+2/2x3+2/3x4+...+2/19x20
Ai nhanh nhất mình tick cho
a) 3/7 + 4/9 + 4/7 + 5/9
= ( 3/7 + 4/7 ) + ( 4/9 + 5/9 )
= 7/7 + 9/9
= 1 + 1
= 2
b)1/5 + 4/10 + 9/15 + 16/20 + 25/25 + 36/30 + 49/35 + 64/40 + 81/45
= 1/5 + 2/5 + 3/5 + 4/5 + 5/5 + 6/5 + 7/5 + 8/5 + 9/5
= ( 1/5 + 9/5 ) + ( 2/5 + 8/5 ) + (7/5 + 3/5 ) + ( 4/5 + 6/5 ) + 5/5
= 2 + 2 + 2 + 2 + 1
= 2 x 4 + 1
= 8 +1
= 9
c) 1/8 + 1/12 + 3/8 + 5/12
= ( 1/8 + 3/8 ) + ( 1/12 + 5/12)
= 4/8 + 6/12
= 1/2 + 1/2
= 2/4 = 1/2
mỏi tay rồi
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tim x, y biet
a, x = -3 b, x-2= 2 c, x-1= x+3
49 7 12 3 9 15
cac ban oi dong ke mo la phan giup min voi thank cac ban nhiu ai giup minh thi minh iu lammmmm
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tim x biet
X+35=-22-X
(6X-4^2) .7^8=2.7^9
5.3^x-1-7.3^12=8.3^12
3.(x-15)^3=-24
lx+18l=10
Bai 1 Tim x biet
a)162+(15-x0=125
b)x^3*x^2=2^7/4
c)5(x+27)=200
d)x-3=6-(19-23)
e)(x+32)-145=92
f) 2*3^x=162
g)9x-9=3^2/3
h)162-(15+x)=148
Bai 2 Thuc hien phep tinh
a)12+14+16+18+...+86+88
b)217+[43+(-217)+(-23)]
c) (-345)+[(-724)+345+224]
d)2^3*3-(12-36)
mình giải ý c
5(x+27)=200
(x+27)=200:5
(x+27)=40
x=40-27
x=13
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Tìm x :
a ) X * 3 ,9 + x * 0 , 1 = 2,7
b ) X * 3 + X * 5 = 9 , 84
c ) 12 , 3 : X - 4 , 5 : X = 15
d ) 7 * X - 2 * X = 1 ,85
a) \(x.3,9+x.0,1=2,7\)
x . (3,9+0,1) = 2,7
x . 4 = 2,7
x = 2,7 : 4
x = 0,675
b) x.3 + x.5 = 9,84
x . ( 3+5) = 9,84
x . 8 = 9,84
x = 9,84 : 8
x = 1,23
c) 12,3:x - 4,5:x = 15
(12,3-4,5) : x = 15
7,8 : x = 15
x = 7,8 : 15
x = 0,52
d) 7.x - 2.x = 1,85
(7-2) . x = 1,85
5 . x = 1,85
x = 1,85 : 5
x = 0,37
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Câu a7/8 chia đóng ngoặc 2/9 - 18 đóng ngoặc + 7/8 x 1/36 - 5/12 câu b 3/7 x 4/9 + 3/7 x 5/9 chia 6/12 câu c 5^8 x 16/31 - 5^8 x 47/31 + 1/3 câu d 7/2 x 3/8 + 7/2 x 5/8 chia 4/15
a: =7/8:(2/9-18+1/36)-5/12
=-7/142-5/12=-397/852
b: =3/7(4/9+5/9:6/12)=2/3
c: =5^8(16/31-47/31)+1/3=-5^8+1/3
d: =7/2(3/8+5/8:4/15)=609/64
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2 TÌM X BIẾT
a, (5x+1)^2 = 36/49
b, (12/25)^x =(5/3)^2 -(-3/5)^4
c, (-3/4)^ 3x-1 = 256/81
d, 172 .x ^2 -7^9 :98^3 =2^3
e,5^x .(5^3)^2 =625
f, (x-2/9)^3 =(2/3)^6
a)\(\left(5x+1\right)^2=\frac{36}{49}\\ \left(5x+1\right)^2=\left(\frac{6}{7}\right)^2\\ \Rightarrow\left[{}\begin{matrix}5x+1=\frac{6}{7}\\5x+1=\frac{-6}{7}\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\frac{-1}{35}\\x=\frac{-13}{35}\end{matrix}\right.\)
vậy...
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2.
a) \(\left(5x+1\right)^2=\frac{36}{49}\)
⇒ \(5x+1=\pm\frac{6}{7}\)
⇒ \(\left[{}\begin{matrix}5x+1=\frac{6}{7}\\5x+1=-\frac{6}{7}\end{matrix}\right.\) ⇒ \(\left[{}\begin{matrix}5x=\frac{6}{7}-1=-\frac{1}{7}\\5x=\left(-\frac{6}{7}\right)-1=-\frac{13}{7}\end{matrix}\right.\) ⇒ \(\left[{}\begin{matrix}x=\left(-\frac{1}{7}\right):5\\x=\left(-\frac{13}{7}\right):5\end{matrix}\right.\)
⇒ \(\left[{}\begin{matrix}x=-\frac{1}{35}\\x=-\frac{13}{35}\end{matrix}\right.\)
Vậy \(x\in\left\{-\frac{1}{35};-\frac{13}{35}\right\}.\)
Chúc bạn học tốt!
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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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