tim so nguyen x biet
(19x + 2.52) : 14 = (13 - 8)2 - 42
-2x3 - 6 = 42 . 3
Tìm x
(19x+2.52) :14= (13-8)2 - 42
\(\left(19x+2.5^2\right):14=\left(13-8\right)^2-4^2\)
\(\Rightarrow\left(19x+50\right):14=5^2-4^2\)
\(\Rightarrow\left(19x+50\right):14=9\)
\(\Rightarrow19x+50=126\)
\(\Rightarrow19x=76\)
\(\Rightarrow x=4\)
Vậy x = 4
#Kễnh
a) 3+2x-1 = 24 - [ 42-(22-1) ]
b) (19x+2.52):14 = (13-8)2-42
a) 3+2x-1 = 24 - [ 42-(22-1) ]
b) (19x+2.52):14 = (13-8)2 - 42
\(a,\Rightarrow2^{x-1}=24-\left(16-3\right)-3\\ \Rightarrow2^{x-1}=24-13-3\\ \Rightarrow2^{x-1}=8=2^3\\ \Rightarrow x-1=3\Rightarrow x=4\\ b,\Rightarrow\left(19x+50\right):14=25-16=9\\ \Rightarrow19x+50=126\\ \Rightarrow x=4\)
Tim so nguyen x biet
(19x + 2.52) : 14 = (13 - 8)2 - 42
-2x3 - 6 = 42 . 3
1.(19x+2.52):14=(13-8)2-42
(19x+2.25):14=52-16
(19x+50):14=25-16
(19x-50):14=9
19x+50=9.14
19x+50=126
19x=126-50
19x=76
x=76:19
x=4 thuộc Z( bạn viết kí hiệu nha!!)
Vậy...
2.-2x3-6=42.3
-2x3-6=16.3
-2x3-6=48
-2x3=48+6
-2x3=54
x3=54:(-2)
x3= -27
x3=(-3)3
=>x= -3 thuộc Z (như trên nha!!)
Vậy...
Chúc bạn học tốt!!
k đúng cho mình nha!!
Bài 5.Tìm x N, sao cho:
a)3636 : (12x –91) = 36
b)(x : 23 + 45) . 67 = 8911
c)[(6x –39) : 7]. 4 = 12
d)(3x –24). 73= 2. 74
e)x(x –10) = 0
f)(x+ 1). (x –2) = 0
g)(9 –x)3= 64
h)3x= 81
i)2 . 3x= 10 . 312+ 8 . 312
j)(19x + 2.52) : 14 = (13 -8)2-42
\(a,\Rightarrow12x-91=101\\ \Rightarrow12x=192\\ \Rightarrow x=16\\ b,\Rightarrow x:23+45=133\\ \Rightarrow x:23=88\\ \Rightarrow x=\dfrac{88}{23}\\ c,\Rightarrow\left(6x-39\right):7=3\\ \Rightarrow6x-39=21\\ \Rightarrow6x=60\\ \Rightarrow x=10\\ d,\Rightarrow3x-24=\dfrac{148}{73}\\ \Rightarrow3x=\dfrac{1900}{73}\\ \Rightarrow x=\dfrac{1900}{219}\\ e,\Rightarrow\left[{}\begin{matrix}x=0\\x=10\end{matrix}\right.\\ f,\Rightarrow\left[{}\begin{matrix}x=-1\\x=2\end{matrix}\right.\\ d,\left(9-x\right)^3=64=4^3\\ \Rightarrow9-x=4\\ \Rightarrow x=5\\ h,\Rightarrow x=27\\ i,\Rightarrow6x=312\cdot12=624\cdot6\\ \Rightarrow x=624\\ j,\Rightarrow\left(19x+104\right):14=25-42=-17\\ \Rightarrow19x+104=-238\\ \Rightarrow19x=-342\\ \Rightarrow x=-18\)
( 19x + 2.52 ) : 14= (13 - 8)2 - 4 tìm x
\(...\Rightarrow\left(19x+50\right):14=5^2-4\Rightarrow\left(19x+50\right):14=21\Rightarrow\left(19x+50\right)=21.14\)
\(\Rightarrow19x+50=294\Rightarrow19x=244\Rightarrow x=\dfrac{244}{19}\)
1) Chung minh 2004^2009 + 2001^n chia het cho 5 (n thuoc N )
2) tim x
a) (15x-3):2=4
b) (19x+2x5^2):14=(13-8)^2 - 4^2
c) 2x3^x=10x3^12+8x27^4
3) tim cac so tu nhien a biet khi chia cho 4 thi duoc 112 va con du
mot nguyen tu X co tong so hat <42.tinh so proton trong nguyen tu X va cho biet X thuoc nguyen to hoa hoc nao trong so cac nguyen to co so proton sau day:C:6;N:7;O:8;Na:11;Mg:12;Al:13;K:19. Biet trong nguyen tu X co 1<n/p<1,5
tim so nguyen x,y biet 42-3|y-3|=4(2012-x)^4