2016 : [ 25 - (3x +2) ] =3^ .7
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
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 \(x=-\frac{2}{3}\)
2016 :[25-(3x+2)]=9.7.2
\(2016:\left[25-\left(3x+2\right)\right]=9.7.2\)
\(\Leftrightarrow2016:\left(25-3x-2\right)=126\)
\(\Leftrightarrow23-3x=2016:126=16\)
\(\Leftrightarrow3x=23-16=7\)
\(\Leftrightarrow x=\frac{7}{3}\)
Bài làm
2016 : [ 25 - ( 3x + 2 ) ] = 9 . 7 . 2
2016 : [ 25 - ( 3x + 2 ) ] = 126
25 - ( 3x + 2 ) = 2016 : 126
25 - ( 3x + 2 ) = 16
3x + 2 = 25 - 16
3x + 2 = 9
3x = 7
x = 7/3
Vậy x = 7/3
# Học tốt #
2016 :[25-(3x+2)]=9.7.2
2016 :[25-(3x+2)] = 126
25-(3x+2) = 2016 : 126
25-(3x+2) =16
3x+2 = 25 - 16
3x + 2 = 9
3x = 9-2
3x = 7
x = 7 : 3
x = 3,5
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
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
Bài 3: Giải các phương trình sau:
a, 2x3 - 50x = 0
b, 2x (3x - 5) - (5 - 3x)
c, 9(3x - 2) = x(2 - 3x)
d, (2x - 1)2 - 25 = 0
e, 25x2 - 2 = 0
f, x2 - 25 = 6x - 9
g, 5x(x - 3) - 2x + 6 = 0
h, 3x(x - 7) - 2(x - 7) = 0
i, 7x2 - 28 = 0
j, (2x + 1) + x(2x + 1) = 0
k, (x + 2)2 - (x - 2)(x + 2) = 0
l, x3 + 5x2 - 4x - 20 = 0
m, x2 - 25 + 2(x + 5) = 0
n, x3 - 3x + 2 = 0
o, x2 - 6x + 8 = 0
p, x2 - 5x - 14 = 0
q, (x - 2)2 - (x - 3)(x + 3) = 6
r, (2x - 1)2 - (2x + 5)(2x - 5) = 18
\(A=\frac{[(\frac{2}{1001}-\frac{3}{2002})\frac{1001}{17}+\frac{33}{34}]}{[(\frac{7}{1008}+\frac{11}{2016})\frac{1008}{25}+\frac{1009}{2016}]}\)
tìm x biết:
3x(2x-5)-6(x2-2x+3)=2016
(2x+3)2.x-7=7-x
b ) [( 6x - 39) : 7] .4 = 12 c) 4( 3x - 4 ) - 2 = 18 d ) ( 3x - 10 ) :10 = 50
e) x- 7 = - 57 f ) x - [ 42 + (-25) = - 8 g) ( 3x - 24 ) . 73 = 2 . 74
h) x + 5 = 20 - ( 12 -7) k) I x - 5 I = 7 - ( -3) i) I x - 5 I = I 7 I
2x+1 . 22009 = 220010 10 - 2x = 25 - 3x
nik lộn
2x+1. 22009 = 22010
10 - 2x = 25 - 3x