Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a) 2/7 + x = -0,75
x= - 3/4 - 2/7
x= 21/28 - 8/28
x = 13/28
Vậy x = 13/28
b) -4 1/5 - x = 2,25
-21/5 - x = 2,25
-x = 2,25 + 21/5
-x = 45/20 + 21/5
-x = 45/20 + 84/20
-x = 84/20
x = -84/20
Vậy x = -84/20
c) x : 8,5 = -2,2
x = -2,2 . 8,5
x = -18,7
Vậy x = -18,7
d) ( 2x/5 - 1 ) : ( -5 ) = 1/7
2x/5 - 1 = 1/7 . ( -5 )
2x/5 - 1 = -5/7
2x/5 = -5/7 + 1
2x/5 = -5/7 + 7/7
2x/5 = 2/7
x = 2/7 : 2/5
x = 2/7 . 5/2
x = 5/7
Vậy x = 5/7
\(2x+\frac{1}{4}=\frac{3}{2}\)
\(\Rightarrow2x=\frac{3}{2}-\frac{1}{4}=\frac{5}{4}\)
\(\Rightarrow x=\frac{5}{4}:2=\frac{5}{8}\)
\(\left(x-5\right)-\frac{1}{3}=\frac{2}{5}\)
\(\Rightarrow x-5=\frac{2}{5}+\frac{1}{3}=\frac{11}{15}\)
\(\Rightarrow x=\frac{11}{15}+5=5\frac{11}{15}\)
các bạn giải giúp mình với thứ 3 là mình phải trả bài rồi!
a/(-5/7)^n+1/(-5/7)^n với n >=1
b/(2x-3)^3=16
c/(3x-2)^5=-234
d/(0,8)^5/(0,4)^6
e/2^15.9^4/6^3.8^3
f/8^10+4^10/8^4+4^11
các bạn giúp gửi câu trả lời về nhanh cho mình nhé!^^
nếu bạn biết bài nào giúp tớ với nhé!!
a) \(\left(4,5-2x\right)\cdot1\frac{4}{7}=\frac{11}{7}\)
\(\left(\frac{9}{2}-2x\right)\cdot\frac{11}{7}=\frac{11}{7}\)
\(\left(\frac{9}{2}-2x\right)=\frac{11}{7}\div\frac{11}{7}\)
\(\left(\frac{9}{2}-2x\right)=1\)
\(2x=\frac{9}{2}-1\)
\(x=\frac{7}{2}\div2\)
\(x=\frac{7}{4}\)
b) \(|\frac{3}{4}\cdot x-\frac{1}{2}|-1=\frac{1}{4}\)
\(|\frac{3}{4}\cdot x-\frac{1}{2}|=\frac{1}{4}+1\)
\(|\frac{3}{4}\cdot x|=\frac{5}{4}+\frac{1}{2}\)
\(x=\frac{7}{4}\div\frac{3}{4}\)
\(x=\frac{7}{3}\)
c) \(\frac{1}{4}-|3-x|=-\frac{3}{4}\)
\(|3-x|=\frac{1}{4}-\left(-\frac{3}{4}\right)\)
\(|3-x|=1\)
\(x=3-1\)
\(\Rightarrow x=2\)
d) \(4\cdot\left(x-\frac{6}{7}\right)-\frac{3}{5}=1,4\)
\(4\cdot\left(x-\frac{6}{7}\right)-\frac{3}{5}=\frac{7}{5}\)
\(4\cdot\left(x-\frac{6}{7}\right)=\frac{7}{5}+\frac{3}{5}\)
\(4\cdot\left(x-\frac{6}{7}\right)=2\)
\(\left(x-\frac{6}{7}\right)=2\div4\)
\(x=\frac{1}{2}+\frac{6}{7}\)
\(x=\frac{19}{14}\)
\(\)
a, \(2x+\dfrac{1}{4}=\dfrac{3}{2}.\)
\(2x=\dfrac{3}{2}-\dfrac{1}{4}.\)
\(2x=\dfrac{6}{4}-\dfrac{1}{4}.\)
\(2x=\dfrac{5}{4}.\)
\(x=\dfrac{5}{4}:2\)
\(x=\dfrac{5}{4.2}=\dfrac{5}{8}.\)
b, \(\left(x-5\right)-\dfrac{1}{3}=\dfrac{2}{5}.\)
\(\left(x-5\right)=\dfrac{2}{5}+\dfrac{1}{3}.\)
\(\left(x-5\right)=\dfrac{6}{15}+\dfrac{5}{15}.\)
\(\left(x-5\right)=\dfrac{11}{15}\)
\(x=\dfrac{11}{15}+5.\)
\(x=\dfrac{11}{15}+\dfrac{75}{15}.\)
\(x=\dfrac{86}{15}.\)
c, \(\left(4,5-2x\right):\dfrac{3}{4}=1\dfrac{1}{3}.\)
\(\left(4,5-2x\right)=1\dfrac{1}{3}.\dfrac{3}{4}.\)
\(\left(4,5-2x\right)=\dfrac{4}{3}.\dfrac{3}{4}.\)
\(4,5-2x=1.\) (vì 2 phân số \(\dfrac{4}{3}\) và \(\dfrac{3}{4}\) nghịch đảo nhau).
\(2x=4,5-1.\)
\(2x=3,5.\)
\(x=3,5:2.\)
\(x=1,75.\)
~ Chúc bn học tốt!!! ~
Bài mik đúng thì nhớ tick mik nha!!! :) :) :)
a)
\(\dfrac{1}{2}x+\dfrac{1}{8}x=\dfrac{3}{4}\\ x\left(\dfrac{1}{2}+\dfrac{1}{8}\right)=\dfrac{3}{4}\\ x\cdot\dfrac{5}{8}=\dfrac{3}{4}\\ x=\dfrac{3}{4}:\dfrac{5}{8}=\dfrac{6}{5}\)
b)
\(\left(2x-4,5\right):\dfrac{3}{4}-\dfrac{1}{3}=1\\\left(2x-\dfrac{9}{2}\right):\dfrac{3}{4}-\dfrac{1}{3}=1\\ \left(2x-\dfrac{9}{2}\right):\dfrac{3}{4}=1+\dfrac{1}{3}=\dfrac{4}{3}\\ \left(2x-\dfrac{9}{2}\right)=\dfrac{4}{3}\cdot\dfrac{3}{4}=1\\ 2x=1+\dfrac{9}{2}=\dfrac{11}{2}\\ x=\dfrac{11}{2}:2=\dfrac{11}{4}\)
a) 1/2 . x + 1/8 . x = 3/4
<=> ( 1/2 + 1/8 ) . x = 3/4
<=> ( 4/8 + 1/8 ) . x = 3/4
<=> 5/8 . x = 3/4
<=> x = 3/4 . 8/5
<=> x = 6/5
Vậy x = 6/5
b) ( 2x - 4,5 ) : 3/4 - 1/3 = 1
<=> ( 2x - 45/10 ) : 3/4 - 1/3 = 1
<=> ( 2x - 9/2 ) : 3/4 - 1/3 = 1
<=> ( 2x - 9/2 ) : 3/4 = 1 + 1/3
<=> ( 2x - 9/2 ) : 3/4 = 4/3
<=> 2x - 9/2 = 4/3 . 3/4
<=> 2x - 9/2 = 1
<=> 2x = 1 + 9/2
<=> 2x = 11/2
<=> x = 11/2 . 1/2
<=> x = 11/4
Vậy x = 11/4