Tìm X biết:
Câu 15: 747 + ( X - 21 . 13 ) : 11 = 786
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
`(2/(11.13)+2/(13.15)+....+2/(19.21)).462-[0,04/(x+1,05):0,12=19`
`=>(1/11-1/13+1/13-1/15+....+1/19-1/21).462-(2/(50(x+1,05)).25/3=19`
`=>(1/11-1/21).462-1/(3(x+1,05))=19`
`=>10/231. 462-1/(3x+3,15)=19`
`=>20-1/(3x+3,15)=19
`=>1/(3x+3,15)=1`
`=>3x+3,15=1`
`=>3x=-2,15`
`=>x=-43/60`
Vậy `x=-43/60`
\(\left(\frac{2}{11\times13}+\frac{2}{13\times15}+\frac{2}{15\times17}+\frac{2}{17\times19}+\frac{2}{19\times21}\right)\times462-x=19\)
\(\left(\frac{1}{11}-\frac{1}{13}+\frac{1}{13}-\frac{1}{15}+...+\frac{1}{19}-\frac{1}{21}\right)\times462-x=19\)
\(\left(\frac{1}{11}-\frac{1}{21}\right)\times462-x=19\)
\(\frac{10}{231}\times462-x=19\)
\(20-x=19\)
\(\Rightarrow x=20-19=1\)
a, (x - 11)5 = 0
=> x - 11 = 0 : 5
=> x - 11 = 0
=> x = 11
vậy_
b, 13(7 - x) = 13
=> 7 - x = 13 : 13
=> 7 - x = 1
=> x = 6
vậy_
bài 2 k hiểu đề nhe
15840 + 7932 x 5
= 15840 + 39660 (0,5 điểm)
= 55500 (0,5 điểm)
(15786 - 13982) x 3
= 1804 x 3 (0,5 điểm)
= 5412 (0,5 điểm)
Tìm x :
(x - 21*13) : 11 = 30
(627 - 56,5) : (x: 2) = 163
2/3 + 1/3 : x = 1
165 - (35 : x + 3) * 15 = 15
a, ( x - 21 . 13 ) : 11 = 30
x - 273 = 30 . 11
x - 273 = 330
x = 330 + 273
x = 603
b, ( 627 - 56,5 ) : ( x : 2 ) = 163
570,5 : ( x : 2 ) = 163
x : 2 = 570,5 : 163
x : 2 = 3,5
x = 3,5 . 2
x = 7
c, 2/3 + 1/3 : x = 1
1/3 : x = 1 - 2/3
1/3 : x = 1/3
x = 1/3 : 1/3
x = 1
d, 165 - ( 35 : x + 3 ) . 15 = 15
165 - ( 35 : x + 3 ) = 15 : 15
165 - ( 35 : x + 3 ) = 1
35 : x + 3 = 165 - 1
35 : x + 3 = 164
35 : x = 164 - 3
35 : x = 161
x = 35 : 161
x = 5/23
Mk tính nhẩm nên chắc có chỗ sai nên bn cứ kiểm tra lại nha
a) \(x+5=20-\left(12-7\right)\)
\(\Rightarrow x+5=20-5\)
\(\Rightarrow x+5=15\)
\(\Rightarrow x=15-5\)
\(\Rightarrow x=10\)
b) \(15-\left(3+2x\right)=2^2\)
\(\Rightarrow3+2x=15-4\)
\(\Rightarrow3+2x=11\)
\(\Rightarrow2x=11-3\)
\(\Rightarrow2x=8\)
\(\Rightarrow x=\dfrac{8}{2}\)
\(\Rightarrow x=4\)
c) \(-11-\left(19-x\right)=50\)
\(\Rightarrow19-x=-11-50\)
\(\Rightarrow19-x=-61\)
\(\Rightarrow x=61+19\)
\(\Rightarrow x=80\)
d) \(159-\left(25-x\right)=43\)
\(\Rightarrow25-x=159-43\)
\(\Rightarrow25-x=116\)
\(\Rightarrow x=25-116\)
\(\Rightarrow x=-91\)
e) \(\left(79-x\right)-43=-\left(17-52\right)\)
\(\Rightarrow\left(79-x\right)-43=52-17\)
\(\Rightarrow79-x-43=35\)
\(\Rightarrow36-x=35\)
\(\Rightarrow x=1\)
f) \(\left(7+x\right)-\left(21-13\right)=32\)
\(\Rightarrow7+x-8=32\)
\(\Rightarrow x-1=32\)
\(\Rightarrow x=32+1\)
\(\Rightarrow x=33\)
g) \(-x+20=-15+8+13\)
\(\Rightarrow-x+20=6\)
\(\Rightarrow x=20-6\)
\(\Rightarrow x=14\)
h) \(-\left(-x+13-142\right)+18=55\)
\(\Rightarrow x-13+142+18=55\)
\(\Rightarrow x+147=55\)
\(\Rightarrow x=55-147\)
\(\Rightarrow x=-92\)
= ( 1/11 - 1/21 ) *4+2-y = 19
= 10/231*4+2-y = 19
= 40/231+2-y = 19
= 502/231-y = 19
= y = 502/231 - 19
= y = một số âm
nha
Câu 15: 747 + ( X - 21 . 13 ) : 11 = 786
<=> (x-273):11=786-747=39
<=>x-273=39.11=429
<=> x=273+429=702