Tìm x: 1-(x-42,6+47,03): 27 phần 4=0
Tìm x biết
a, 25%.x=42,6-3,28. c, 7011/25÷(x-42,6)=117,14-47,03
b, x÷40%=7,25+6,75. d, 0,3 .(x+1/3)=1/2.(0,81÷27)
\(a,25\%x=42,6-3,28\\ \Leftrightarrow\dfrac{1}{4}x=39,32\\ \Leftrightarrow x=157,28\)
\(b,x:40\%=7,25+6,75\\ \Leftrightarrow x:40\%=14\\ \Leftrightarrow x=5,6\)
\(c,\dfrac{7011}{25}:\left(x-42,6\right)=117,14-47,03\\ \Leftrightarrow\dfrac{7011}{25}:\left(x-42,6\right)=70,11\\ \Leftrightarrow x-42,6=4\\ \Leftrightarrow x=46,6\)
\(d,0,3\left(x+\dfrac{1}{3}\right)=\dfrac{1}{2}\cdot\left(0,81:27\right)\\ \Leftrightarrow0,3\left(x+\dfrac{1}{3}\right)=0,015\\ \Leftrightarrow x+\dfrac{1}{3}=0,05\\ \Leftrightarrow x=-\dfrac{17}{60}\)
a,7011/25:(x-42,6)=117,14-47,03
b,0,3x(x+1/3)=1/2(0,81:2,7)
\(a,\frac{7011}{25}:\left(x-42,6\right)=117,14-47,03\)
\(=\frac{7011}{25}:\left(x-42,6\right)=70,11\)
\(\Rightarrow\left(x-42,6\right)=\frac{7011}{25}:70,11\)
\(\Rightarrow x=4+42,6\)
\(\Rightarrow x=46,6\)
Phần a thì có bạn giải rồi nên mình sẽ giải phần b :
0,3 x ( X+ (1)/(3) ) =(1)/(2) x (0,81 : 2,7)
0,3 nhan (x +1/3)=1/2nhan (0,81:2,7)
7011:(x-42,6)=117,14-47,03
(2,7-0,8)nhân 2/1/3 /(5,2-1,4):3/7 + x-8/9/11=2,625
(x+0,2)+(x+0.7)+(x+1,2)+.......+(x+4,2)+(x+4,7)=65,5
45/10/63 -44/25/84 /3/4- (2/1/3-1/1/9):31/4=1/16:x
mình cần gấp các bạn ạ mong các bạn giải nhanh giúp mình
tìm x biết x-13/87+x-27/73+x-67/33+x-73/27=|1-4|.2019^0+1
tìm x:..(x-1)^4 - 27|x-1|=0
Tìm x biết :
x + 256,5 = 786,89 42,6 : x= 12
Tìm x biết :
a, x + 256,5 = 786,89
b, 42,6 : x = 12
a, x + 256,5 = 786,89
x = 786,89 - 256,5
x = 530,39
b, 42,6 : x = 12
x = 12 x 42,6
x = 511,2
1/phân tích thành phân tử
a. x^6 - 64
b. x^3+3x^2 + 3x+1- y^3
c. x^3 - 27+ x( x-3)
d, y^6 - 625
2/tìm x biết
a. 25x^2 -1=0
b. 4 (x-1)^2 -9 =0
c. 1/4 -9(x-1)^2 =0
d. 1/16 - ( 2x + 3/4) ^2 =0
1/4 nghĩa là 1 phần 4 á nhé, nhờ giúp đỡ
2/
a/ \(25x^2-1=0\)
<=> \(\left(5x\right)^2-1=0\)
<=> \(\left(5x-1\right)\left(5x+1\right)=0\)
<=> \(\orbr{\begin{cases}5x-1=0\\5x+1=0\end{cases}}\)<=> \(\orbr{\begin{cases}x=\frac{1}{5}\\x=-\frac{1}{5}\end{cases}}\)
b/ \(4\left(x-1\right)^2-9=0\)
<=> \(\left[2\left(x-1\right)\right]^2-3^2=0\)
<=> \(\left(2x-2\right)^2-3^2=0\)
<=> \(\left(2x-2-3\right)\left(2x-2+3\right)=0\)
<=> \(\left(2x-5\right)\left(2x+1\right)=0\)
<=> \(\orbr{\begin{cases}2x-5=0\\2x+1=0\end{cases}}\)<=> \(\orbr{\begin{cases}x=\frac{5}{2}\\x=-\frac{1}{2}\end{cases}}\)
c/ \(\frac{1}{4}-9\left(x+1\right)^2=0\)
<=> \(\left(\frac{1}{2}\right)^2-\left[3\left(x-1\right)\right]^2=0\)
<=> \(\left(\frac{1}{2}\right)^2-\left(3x-3\right)^2=0\)
<=> \(\left(\frac{1}{2}-3x+3\right)\left(\frac{1}{2}+3x-3\right)=0\)
<=> \(\left(\frac{7}{2}-3x\right)\left(-\frac{5}{2}+3x\right)=0\)
<=> \(\orbr{\begin{cases}\frac{7}{2}-3x=0\\-\frac{5}{2}+3x=0\end{cases}}\)<=> \(\orbr{\begin{cases}3x=\frac{7}{2}\\3x=\frac{5}{2}\end{cases}}\)
<=> \(\orbr{\begin{cases}x=\frac{7}{6}\\x=\frac{5}{6}\end{cases}}\)
d/ \(\frac{1}{16}-\left(2x+\frac{3}{4}\right)^2=0\)
<=> \(\left(\frac{1}{4}\right)^2-\left(2x+\frac{3}{4}\right)^2=0\)
<=> \(\left(\frac{1}{4}-2x-\frac{3}{4}\right)\left(\frac{1}{4}+2x+\frac{3}{4}\right)=0\)
<=> \(\left(-\frac{1}{2}-2x\right)\left(1+2x\right)=0\)
<=> \(2\left(-\frac{1}{4}-x\right)\left(1+2x\right)=0\)
<=> \(\orbr{\begin{cases}-\frac{1}{4}-x=0\\1+2x=0\end{cases}}\)<=> \(\orbr{\begin{cases}x=-\frac{1}{4}\\x=-\frac{1}{2}\end{cases}}\)
Tìm x
1)7.(x-1) +2x.(x-1) =0
2)2x.(x-3)+9x-27=0
3)4.(x-1/2)+4.(5-x)=9/2
Ta có : 7(x - 1) + 2x(x - 1) = 0
<=> (2x + 7)(x - 1) = 0
\(\Leftrightarrow\orbr{\begin{cases}2x+7=0\\x-1=0\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}2x=-7\\x=1\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=-\frac{7}{2}\\x=1\end{cases}}\)
2) Ta có : 2x(x - 3) + 9x - 27 = 0
<=> 2x(x - 3) + 9(x - 3) = 0
<=> (x - 3)(2x + 9) = 0
\(\Leftrightarrow\orbr{\begin{cases}x-3=0\\2x+9=0\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=3\\2x=-9\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=3\\x=-\frac{9}{2}\end{cases}}\)