2016 :[25-(3x+2)]=9.7.2
2016 : [ 25 - (3x +2) ] =3^ .7
2016 : \(\left[25-\left(3x+2\right)\right]=3^7\)
<=> 25 - (3x + 2) = 2016 : 2187
<=> 25 - 3x - 2 = \(\dfrac{224}{243}\)
<=> -3x = \(\dfrac{224}{243}\) + 2 - 25
<=> -3x = \(\dfrac{-5365}{243}\)
<=> x = 7,359396433 \(\approx\) 7,4
2016 : \(\left[25-\left(3x+2\right)\right]=3^2\)
<=> 25 - (3x + 2) = 2016 : 9
<=> 25 - 3x - 2 = 224
<=> -3x = 224 - 25 + 2
<=> -3x = 201
<=> x = \(\dfrac{201}{-3}=-67\)
Bài 8: Tìm số nguyên x, biết: 2016 : [25 – (3x + 2)] = 32 .7
thanks
Ta có: \(2016:\left[25-\left(3x+2\right)\right]=32\cdot7\)
\(\Leftrightarrow25-\left(3x+2\right)=9\)
\(\Leftrightarrow3x+2=16\)
\(\Leftrightarrow3x=14\)
hay \(x=\dfrac{14}{3}\)
2016 : [25 - (3x+2)]=32.7
25 - (3x+2)= 2016 : 224
25 - (3x+2)= 9
3x+2 = 16
3x=14
x=\(\dfrac{14}{3}\)
2016 : [25 - (3x+2)]=32.7
25 - (3x+2)= 2016 : 224
25 - (3x+2)= 9
3x+2 = 16
3x=14
x=14/3
giải pt
`(2x^2 +x-2016)^2 +4(x^2 -3x-1000)^2 = 4(2x^2 +x-2016)(x^2 -3x-1000)`
Đặt: \(\left\{{}\begin{matrix}a=2x^2+x-2016\\b=x^2-3x-1000\end{matrix}\right.\). Phương trình trở thành:
\(a^2+4b^2=4ab\)
\(\Leftrightarrow a^2-4ab+4b^2=0\)
\(\Leftrightarrow\left(a-2b\right)^2=0\Leftrightarrow a=2b\)
\(\Rightarrow2x^2+x-2016=2\left(x^2-3x-1000\right)\)
\(\Leftrightarrow7x=16\Leftrightarrow x=\dfrac{16}{7}\)
Vậy: \(x=\dfrac{16}{7}\)
Tìm x thuộc Q biết:
(2/3x-1).(3/4x + 1/2) = 0
Thời hạn là trước ngày 25/7/2016 nha!!
Ai trả lời đúng nhất là đc tick nha!!!
Thanks m.n!!
\(\left(\frac{2}{3}x-1\right)\left(\frac{3}{4}x+\frac{1}{2}\right)=0\)
=>\(\frac{2}{3}x-1=0\) hoặc \(\frac{3}{4}x+\frac{1}{2}=0\)
+)Nếu \(\frac{2}{3}x-1=0\)
=>\(\frac{2}{3}x=1\Rightarrow x=\frac{3}{2}\)
+)Nếu \(\frac{3}{4}x+\frac{1}{2}=0\)
=>\(\frac{3}{4}x=-\frac{1}{2}\Rightarrow x=-\frac{2}{3}\)
Vậy \(x=\frac{3}{2}\) hoặc \(x=-\frac{2}{3}\)
Tìm x biết:
a)(3x-6)(8+2x)=0
b)(x-2)(x+3)<0
c)(x^2-5)(x^2-25)<0
d) /x+2015/+/x-2016/=4031 (/,/)là giá trị tuyệt đối)
Bài 1: Tính
a) - ( 515 - 80 + 91 ) - ( 2003 + 80 - 91 )
b) - 2016 + 57 + 2016 - 257 + 100
Bài 2: Tìm x, biết
a) 25 - ( 30 + x ) = - ( 3x - 27 )
b) ( x - 12 ) - 15 = ( 20 - 7 ) - ( 18 + x )
c) | x - 5 | - 10 = 3
Các bạn ghi cách giải cho mình nhé
giải phương trình vô tỉ sau
\(\sqrt[2016]{x^2+3x-3}+\sqrt[2016]{-x^2-3x+5}=2\)
Tìm x biết:
1) x (x-2016) + 2015 (2016-x) = 0
2) -5x (x-15) + (15-x) = 0
3) 3x (3x-7) - (7-3x) =0
1) x (x-2016) + 2015 (2016-x) = 0
x (x-2016) - 2015 (x- 2016) = 0
(x-2015)(x-2016) =0
\(\Rightarrow\orbr{\begin{cases}x-2015=0\\x-2016=0\end{cases}\Rightarrow\orbr{\begin{cases}x=2015\\x=2016\end{cases}}}\)
Vậy x= 2015; 2016
2) -5x (x-15) + (15-x) = 0
-5x (x-15) - (x-15) =0
(-5x -1) (x-15) =0
\(\Rightarrow\orbr{\begin{cases}-5x-1=0\\x-15=0\end{cases}\Rightarrow\orbr{\begin{cases}-5x=1\\x=15\end{cases}\Rightarrow}\orbr{\begin{cases}x=-\frac{1}{5}\\x=15\end{cases}}}\)
Vậy x= -1/5; 15
3) 3x (3x-7) - (7-3x) =0
3x(3x-7) + (3x -7) =0
(3x+1) (3x-7) =0
\(\Rightarrow\orbr{\begin{cases}3x+1=0\\3x-7=0\end{cases}\Rightarrow\orbr{\begin{cases}3x=-1\\3x=7\end{cases}\Rightarrow}\orbr{\begin{cases}x=-\frac{1}{3}\\x=\frac{7}{3}\end{cases}}}\)
Vậy x= -1/3 ; 7/3
\(\lim\limits_{x\rightarrow0}\dfrac{\left(x^2+2016\right)\sqrt[3]{1+3x}-2016}{x}\)
\(=\lim\limits_{x\rightarrow0}\dfrac{\left(x^2+2016\right)\left(\sqrt[3]{1+3x}-1\right)+x^2}{x}=\lim\limits_{x\rightarrow0}\dfrac{\dfrac{3x\left(x^2+2016\right)}{\sqrt[3]{\left(1+3x\right)^2}+\sqrt[3]{1+3x}+1}+x^2}{x}\)
\(=\lim\limits_{x\rightarrow0}\left(\dfrac{3\left(x^2+2016\right)}{\sqrt[3]{\left(1+3x\right)^2}+\sqrt[3]{1+3x}+1}+x\right)=\dfrac{3.2016}{3}=2016\)