30% - 1 1/5 +1,5 X -1/2 =?
GIUP MINK VOI
1+2+3+....+ x =465
giup mink voi can gap
ai giup mink ba cau nay voi a,|x-5|=|-3x+2| b,|x-5|+|x^2-25|=0 c,|2x-3|+|2x+4|=7
tìm x biết
a,3/4x-1/5=7/4x+11/5
b,x+1/2=8/x+1
các bạn giup mink vs nha mink ngu toán
a, \(\frac{3}{4}x-\frac{1}{5}=\frac{7}{4}x+\frac{11}{5}\)
\(\Rightarrow\frac{3}{4}x-\frac{7}{4}x=\frac{11}{5}+\frac{1}{5}\)
\(\Rightarrow-x=\frac{12}{5}\Rightarrow x=-\frac{12}{5}\)
Vậy ...
b, \(\frac{x+1}{2}=\frac{8}{x+1}\)
\(\Rightarrow\left(x+1\right)^2=16\)
\(\Rightarrow x+1=4\)hoặc \(x+1=-4\)
\(\Rightarrow x=3\) hoặc \(x=-5\)
Vậy ..
3/4x-7/4x=1/5+11/5
(3/4-7/4).x=12/5
-1.x=12/5
x=12/5:-1
x=-12/5
vậy x=-12/5
a,\(\frac{3}{4}x-\frac{1}{5}=\frac{7}{4}x+\frac{11}{5}\)
\(< =>\frac{3x}{4}-\frac{7x}{4}=\frac{11}{5}+\frac{1}{5}=\frac{12}{5}\)
\(< =>-\frac{4x}{4}=\frac{12}{5}< =>-x=\frac{12}{5}\)
\(< =>x=-\frac{12}{5}\)
b, \(x+\frac{1}{2}=\frac{8}{x}+1\left(đk:x\ne0\right)\)
\(< =>x-\frac{8}{x}=1-\frac{1}{2}=\frac{1}{2}\)
\(< =>\frac{x^2-8}{x}=\frac{1}{2}\)
\(< =>2x^2-16=x\)
\(< =>2x^2-x+16=0\)
\(\Delta=\left(-1\right)^2-4.2.16 < 0\)
Vô nghiệm :V bài này sai đề
175-95:[(2+8.2).9^0+1^9
giup mink voi mik nghi nen ko biet
= 175 - 95 :(18.1+1)
= 175-95 :19
= 175-5
170
chung minh rang 4+4^3+4^5+4^7+...+4^23 chia het cho 68
chung minh rang 1+3+3^2+3^3+...+3^2000 chia het cho 13
giup mink voi thu 6 mink nop roi
4 + 4^3 + 4^5 + 4^7 + ... + 4^23
= ( 4 + 4^3 ) + ( 4^5 + 4^7 ) +.....+ ( 4^22 + 4^23)
=4( 1+16 ) + 4^5( 1+16 ) +....+ 4^22( 1+ 16 )
=4 x 17 + 4^5 x 17+....+ 4^22 x 17 chia hết cho 68
Câu 2:
1+3+3^2+3^3+....+3^2000
=( 1+3 +3^2 ) + ( 3^3 + 3^4 + 3^5 ) +.....+ ( 3^ 1998 + 3^1999 + 3^2000)
=1( 1+ 3 + 9 ) + 3^3 + ( 1+ 3 + 9 ) +......+ 3^1998+( 1+ 3 + 9 )
= 1 x 13+ 3^3 x 13 +......+ 3^1998 x 13 chia hết cho 13
k mk nha lần sau mk k lại
Câu 1 nha : 4+4^3+4^5+4^7+....+4^23 = (4+4^3)+(4^5+4^7)+....+(4^21+4^23)
= 68 + 4^4.(4+4^3)+....+4^20.(4+4^3) = 68 + 4^4.68 + .... + 4^20.68
=68.(1+4^4+....+4^20) chia hết cho 68
Câu 2 nha 1+3+3^2+...+3^2000 = (1+3+3^2)+(3^3+3^4+3^5)+....+(3^1998+3^1999+3^2000)
= 13 + 3^3.(1+3+3^2)+....+3^1998.(1+3+3^2) = 13+3^3.13+....+3^1998.13
=13.(1+3^3+....+3^1998) chia hết cho 13
\(\left(\frac{2x}{3}-3\right):\left(-10\right)=\frac{2}{5}\)
\(1,5x-2\frac{1}{3}x=1,5-\frac{2}{3}\)
Giup minh voi
a) \(\left(\frac{2x}{3}-3\right):\left(-10\right)=\frac{2}{5}\)
<=> \(\frac{2x}{3}-3=\frac{2}{5}.\left(-10\right)\)
<=> \(\frac{2x}{3}-3=-4\)
<=> \(\frac{2x}{3}=-4+3=-1\)
<=> \(2x=-1.3=-3\)
<=> \(x=\frac{-3}{2}\)
Vậy \(x=\frac{-3}{2}\)
b) \(1,5x-2\frac{1}{3}x=1,5-\frac{2}{3}\)
\(x.\left(1,5-2\frac{1}{3}\right)=\frac{5}{6}\)
\(x.\left(\frac{-5}{6}\right)=\frac{5}{6}\)
\(x=\frac{5}{6}:\left(\frac{-5}{6}\right)=\frac{5}{6}.\left(\frac{-6}{5}\right)=-1\)
Vậy \(x=-1\)
Nếu đúng thì cho mình nhé, chúc bạn học tốt !
2015 ×(2015-1)×(2015-2)×(2015-3)×...(2015-k)
Voi k€ N va tich trên co dung 2016 thua so.
May ban giup mink nhanh chóng thi mink tick cho nha.
kết quả phép tính này =0 nha bạn
k mik nha.
Tim x :7/12 < X / 24 < 2 /3.giup mik voi,mink can lam,xin day
\(\dfrac{7}{12}< \dfrac{x}{24}< \dfrac{2}{3}\)
→ \(\dfrac{7}{12}=\dfrac{7x2}{12x2}=\dfrac{14}{24}\)
→ \(\dfrac{2}{3}=\dfrac{2x8}{3x8}=\dfrac{16}{24}\)
⇒ x\(=\)15
\(\Leftrightarrow14< x< 16\)
hay x=15
3/5;x=1/3+1/2 giup minh voi
3/5 x = 5/6
x = 5/6 : 3/5
x = 25/18
\(\dfrac{3}{5}:x=\dfrac{1}{3}+\dfrac{1}{2}\)
\(\dfrac{3}{5}:x=\dfrac{5}{6}\)
\(x=\dfrac{3}{5}:\dfrac{5}{6}\)
\(x=\dfrac{18}{25}\)
3/5:*=1/3+1/2
3/5:*=5/6
*=5/6:3/5
*=25/18