(X-291):1700+(X-293):1698+(x-295):1696+(x-297):1694=4
Tìm x
\(\dfrac{x-291}{1700}\)+\(\dfrac{x-293}{1698}\)+\(\dfrac{x-295}{1696}\)+\(\dfrac{x-297}{1694}\)=4
trừ hai vế của PT cho 4 . ta được
\(\dfrac{x-291}{1700}-1+\dfrac{x-293}{1698}-1+\dfrac{x-295}{1696}-1+\dfrac{x-297}{1694}-1=4-4\)
<=> \(\dfrac{x-291-1700}{1700}+\dfrac{x-293-1698}{1698}+\dfrac{x-295-1696}{1696}+\dfrac{x-297-1694}{1694}=0\)
<=> \(\dfrac{x-1991}{1700}+\dfrac{x-1991}{1698}+\dfrac{x-1991}{1696}+\dfrac{x-1991}{1694}=0\)
<=> (x-1991)\(\left(\dfrac{1}{1700}+\dfrac{1}{1698}+\dfrac{1}{1696}+\dfrac{1}{1694}\right)=0\)
<=> x - 1991 = 0 ( vì \(\dfrac{1}{1700}+\dfrac{1}{1698}+\dfrac{1}{1696}+\dfrac{1}{1694}\)luôn lớn hơn 0 với mọi x)
<=> x = 1991
vậy x=1991
Giải phương trình:
a) \(\dfrac{x-3}{113}+\dfrac{x-5}{115}=\dfrac{x-7}{117}+\dfrac{x-9}{119}\)
b) \(\dfrac{x-291}{1700}+\dfrac{x-293}{1698}+\dfrac{x-295}{1696}+\dfrac{x-297}{1694}=4\)
Giúp mình với!!! Mình cần gấp!!!
https://giaibaitapvenha.blogspot.com/2017/12/toan-lop-8-ai-so-giai-phuong-trinh.html
Nếu lời giải giúp ích được cho bạn, truy cập
https://giaibaitapvenha.blogspot.com/2017/12/en-voi-do-homework-for-you-e-trai.html
a,\(\dfrac{x-3}{113}+\dfrac{x-5}{115}=\dfrac{x-7}{117}+\dfrac{x-9}{119}\)
=>\(\dfrac{x-3}{113}+1+\dfrac{x-5}{115}+1=\dfrac{x-7}{117}+1+\dfrac{x-9}{119}+1\)
=>\(\dfrac{x+110}{113}+\dfrac{x+110}{115}=\dfrac{x+110}{117}+\dfrac{x+110}{119}\)
=>(x+110)(\(\dfrac{1}{113}+\dfrac{1}{115}-\dfrac{1}{117}-\dfrac{1}{119}\))=0
vì 1/113+1/115-1/117-1/119 khác 0
=>x+110=0=>x=-110
\(\dfrac{x-291}{1700}+\dfrac{x-293}{1698}+\dfrac{x-295}{1696}+\dfrac{x-297}{1694}=4\)
=>\(\dfrac{x-291}{1700}-1+\dfrac{x-293}{1698}-1+\dfrac{x-295}{1696}-1+\dfrac{x-297}{1694}-1+4=4\)=>\(\dfrac{x-1991}{1700}+\dfrac{x-1991}{1698}+\dfrac{x-1991}{1696}+\dfrac{x-1991}{1694}=0\)
=>(x-1991)(1/1700+1/1698+1/1696+1/1694)=0
vì 1/1700+1/1698+1/1696+1/1694 khác 0
=>x-1991=0=>x=1991
có bao nhiêu hinh tam giác??ai nhanh và đúng mk tick cho
1. Tính
a) 201 + 20 - 112
b) 2190 + 1029 - 9299
c) 999 - 999 + 999 - 999
d) 291 - 912 + 12910
2. Tìm x
a) 29x + 3029 = 3870
b) (x + 3928) - 2019 = 2000000
c) -3x - 201 = -441
d) 291 - 293 + x = 293
e) 283 + 10x = 1283
*Những bài này ko sai đề wwwwwwwwwwwwwwwwwwwww
1. a) 201+20-112= 221-112= 109
b) 2190+1029-9299= 3219-9299= -5880
c) 999-999+999-999= 0+0=0
d) 291-912+12910= -693+ 12910= 12217
2. a) 29x+3029= 3870
=> 29x= 3870-3029=841
=> x= 841: 29
=> x=29
b) (x+3928)-2019= 2000000
=> x+3928= 2000000+ 2019= 2002019
=> x= 2002019
c) -3x-201=-441
=> -3x= -441+ 201= -240
=> x= 80
d) 291-293+x= 293
=> -2+x= 293
=>x= 293+2=295
e) 283+ 10x= 1283
=> 10x= 1283-283= 1000
=> x=3
Tìm x biết x:5+174=1694
x:5+174=1694
x:5=1694-174
x:5=1520
x=1520.5
x=7600
tìm x :
x:
5+174=1694
x : 5 = 1694 - 174 = 1520
x = 1520 . 5
x = 7600
1698 - x = 458
x =?
1698 - x = 458
x = 1698 - 458
x = 1240
1698-x=458
x=1698-458
x=1240
nho **** cho minh nhe !
Cho x:3 dư 2, x:5 dư 1, x:7 dư 4, x trong khoảng từ 1700 đến 1800
goi so tn can tim la x (x N)
vi so tn do khi chia cho 3du 2 nen x:3du2 suy ra 2x:3du1 suy ra (2x-1)chia het cho3
2=x=? co tong 1696 la so chan