115-20:5.x=95
115- x : 5 = 20
\(115-x\div5=20\)
\(x\div5=115-20\)
\(x\div5=95\)
\(x=95\times5\)
\(x=475\)
115 - x : 5 = 20
x : 5 = 115 - 20
x : 5 = 95
x = 95 x 5
x = 475
Hok tốt
\(115-x:5=20\)
\(< =>115-\frac{x}{5}=20\)
\(< =>\frac{x}{5}=115-20=95\)
\(< =>x=95.5=475\)
Câu 1 : Tính :
a, (-115)+(-40)+115+|-35|
b, [ 189 - [34+20-5)]] : 20
Câu 2 : Tìm số nguyên x biết :
a, x - 15 = 20 . 2 mũ 2
b, 48 + 5(x-3)=63
c, |x| - 2 = 7-(-8)
a, (-115)+(-40)+115+|-35|
=[(-115) +115] + [(-40) +35]
=-5
b)[ 189 - (34+20-5)] : 20
= (189-49) :20
= 140:20 =7
2.a) x-15= 20.22
<=> x-15 = 80
<=> x=80 + 15
<=> x=95
VẬy x=95
b) 48 +5(x-3) = 63
<=> 5(x-3) = 63-48
<=> 5(x-3) =15
<=> x-3 = 15:5
<=>x-3 = 3
<=> x=6
Vậy x=6
c) |x| -2 = 7-(-8)
<=> |x| -2 = 15
<=> |x| =15+2
<=> |x| = 17
<=>\(\left[{}\begin{matrix}x=17\\x=-17\end{matrix}\right.\)
Vậy x=17 hoặc x=-17
x+5/95 + x+10/90 + x+15/85 + x+20/80=4
tìm x:
a)200-3x(x-16)=20
b)5+10+15+...+95+100+x=1200
c)x+(99-97+95-93+91-89+...+7-5+3-1)=100
a, 200 - 3( x - 16 ) = 20
3( x - 16 ) = 200 - 20 = 180
x - 16 = 180 : 3 = 60
x = 60 + 16 = 76
b, 5 + 10 + 15 + .............. + 95 + 100 + 105 = 1200
c, x + ( 99 - 97 + 95 - 93 + ............ + 7 - 5 + 3 - 1 ) = 100
x + ( 2 . 25 ) = 100
x + 50 = 100
x = 100 - 50 = 50
****, thks
(617/191+29/33-115/117)x(1/4-1/5-1/20)
(617/191+29/33-115/117)*(1/4-1/5-1/20)
= (617/191+29/33-115/117)*(5/20-4/20-1/20)
=(617/191+29/33-115/117)*0
=0
\(\left(\dfrac{617}{191}+\dfrac{29}{33}-\dfrac{115}{117}\right)\times\left(\dfrac{1}{4}-\dfrac{1}{5}-\dfrac{1}{20}\right)\\ =\left(\dfrac{617}{191}+\dfrac{29}{33}-\dfrac{115}{117}\right)\times0\\ =0\)
Tìm x
15+4.(x-2)=95
20-(x+14)=5
1. 15 + 4.(x-2) = 95
4.(x-2) = 95-15
4.(x-2) = 80
x - 2 = 80 : 4
x- 2 = 20
x=18
2. 20 - (x+14)=5
x+14=20-5
x+14=15
x =15-14
x= 1
- 15+4(x-2)=95
4(x-2)=95-15
4(x-2)=80
x-2 =80:4
x-2 =20
x =20+2
x =22
- 20-(x+14)=5
(x+14)=20-5
x+14=15
x =15-14
x =1
\(4.\left(x-2\right)=95-15\)
\(4.\left(x-2\right)=80\)
\(x-2=80:4\)
\(x-2=20\)
\(x=20+2\)
\(x=22\)
\(x+14=20-5\)
\(x+14=15\)
\(x=15-14\)
\(x=1\)
bài 1 : 101 x 125 + 101 x 25 - 101 x 50
bài 2 : 76 x 115 + 56 x 24 + 59 x 24
bài 3 : thực hiện phép tính : a ) 90-84+ 8 - 72 +66-60+54-48
b ) 99-97+95-93+91-89+.........+7-5+3-1
bài 4 : tìm số tự nhiên x biết :
a) \(x\) x 16 -\(x\) x 9 = 56
bài 5 :tìm số tự nhiên x , biết
a) \(x\) + 2 x \(x\) +3 x \(x\)+4 x \(x\) +5 x \(x\) = 165
b ) 1+2+3+4+.....+\(x\)=55
GIẢI GIÚP E Ạ
Bài 1:
\(101\cdot125+101\cdot25-101\cdot50\)
\(=101\cdot\left(125+25-50\right)\)
\(=101\cdot100\)
\(=10100\)
Bài 2:
\(76\cdot115+56\cdot24+59\cdot24\)
\(=76\cdot115+24\cdot\left(56+59\right)\)
\(=76\cdot115+24\cdot115\)
\(=115\cdot\left(76+24\right)\)
\(=115\cdot100\)
\(=11500\)
5:
a: =>15x=165
=>x=11
b: =>x(x+1)/2=55
=>x^2+x=110
=>x=10
4: =>7x=56
=>x=8
Bài 1:
101•125+101•25+101•50
= 101•(125+25-50)
=101•100
=10100
Bài 2:
76•115+56•24+59•24
= 76•115+24•(56+59)
= 76•115+24•115
= 115•(76+24)
= 115•100
= 11500
\(\frac{x+5}{95}+\frac{x+10}{90}+\frac{x+15}{85}+\frac{x+20}{80}=-4\)
\(\frac{x+5}{95}+\frac{x+10}{90}+\frac{x+15}{85}+\frac{x+20}{80}=-4\)
<=> \(\frac{x+5}{95}+1+\frac{x+10}{90}+1+\frac{x+15}{85}+1+\frac{x+20}{80}+1=0\)
<=> \(\frac{x+100}{95}+\frac{x+100}{90}+\frac{x+100}{85}+\frac{x+100}{80}=0\)
<=> \(\left(x+100\right)\left(\frac{1}{95}+\frac{1}{90}+\frac{1}{85}+\frac{1}{80}\right)=0\)
<=> \(x+100=0\) (do 1/95 + 1/90 + 1/85 + 1/80 khác 0)
<=> \(x=-100\)
Vậy...
Tính giá trị của biểu thức:
a)12 x 5 + 12 x 95
b) 10 x 20 x 5 x 10
( Tính hợp lí nếu có thể )
a. 12x5+12x95=12x(5+95)=12x100=1200
b. 10x20x5x10=(10x10)x(20x5)=100x100=10000
tk nha
a, 12.5+12.95=12.(5+95)
=12.100
=1200
b,10.20.5.10=(10.10).(20.5)
=100.100
=10000
a) \(12\times5+12\times95\)
\(=12\times\left(5+95\right)\)
\(=12\times100\)
\(=1200\)
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