Tìm x biết :\(|2x-6|+5x=9\)
Tìm x, biết (4x − 9) + (5x − 7) − (2x + 6) = 7
=>4x-9+5x-7-2x-6=7
=>7x-22=7
=>7x=29
=>x=29/7
Tìm x, biết:
a. | 7 - x | - | 2x + 5 | < 2x - 3
b. | -5x + 3 | - | 2x - 3 | > x + 2
c. | 7x | + | -5x +9 | < 6
Tìm x biết:
|2x-6|+5x=9
+)X\(\ge\) 3 => (2x-6)+5x=9
2x-6+5x=9
2x+5x=9+6
7x=15
x=\(\frac{15}{7}\) (loại)
+) x<3 => -(2x-6)+5x=9
-2x+6+5x=9
-2x+5x=9-6
3x=3
x=1
KL: x=1
Tìm x biết :
a, 4.(18 - 5x) - 12.(3x - 7) = 15.(2x - 16) - 6(x + 14)
b, 5.(3x + 5) - 4.(2x - 3) = 5x + 3.(2x + 12) + 1
c, 2.(5x - 8) - 3.(4x - 5) = 4.(3x - 4) + 11
d, (3x + 2)(2x + 9) - (x + 2)(6x + 1) = (x + 1) - (x - 6)
e, (8x - 3)(3x + 2) - (4x + 7)(x + 4)= (2x + 1)(5x - 1) - 33
Noob ơi, bạn phải đưa vào máy tính ý solve cái là ra x luôn, chỉ tội là đợi hơi lâu
a, 4.(18 - 5x) - 12(3x - 7) = 15(2x - 16) - 6(x + 14)
=> 72 - 20x - 36x + 84 = 30x - 240 - 6x - 84
=> (72 + 84) + (-20x - 36x) = (30x - 6x) + (-240 - 84)
=> 156 - 56x = 24x - 324
=> 24x + 56x = 324 + 156
=> 80x = 480
=> x = 480 : 80 = 6
Vậy x = 6
b, 5(3x + 5) - 4(2x - 3) = 5x + 3(2x + 12) + 1
=> 15x + 25 - 8x + 12 = 5x + 6x + 36 + 1
=> (15x - 8x) + (25 + 12) = 11x + 37
=> 7x + 37 = 11x + 37
=> 11x - 7x = 0
=> x = 0
Bài 2 : Tìm x , biết
a) ( 3x -1 ) (2x+7) - ( x +1) (6x-5 ) = 16
b) ( 10x +9 )x - ( 5x -1 ) (2x+3 )= 8
c) ( 3x - 5 ) ( 7- 5x ) + ( 5x +2 )( 3x-2 ) -2 = 0
d) x(x + 1) ( x+6 ) - x3 = 5x
Tìm x biết
a) 5x+2x=6^2-5^0
b)6x+x=5^11:5^9+3^1
c)5x+3x=3^6:3^3.4+12
a) 5x + 2x = 6^2 - 5^0
7x = 35
x=5
b) 6x + x = 5^11 : 5^9 + 3^1
7x = 28
x=4
c) 5x + 3x = 3^6 : 3^3 *4 +12
8x = 120
x=15
tìm x biết :
a) 2 . |5x-3| - 2x = 14
b) |3x-2| - x = 7
c) |4x+3| - x = 15
d) |3x-2| + 5x = 4x -10
e) |3x-2| + 5x = 4x-10
f) |2x-6| + 5x = 9
g) |5x-3| - x = 7
a) \(2.\left|5x-3\right|-2x=14\)
\(2\left|5x-3\right|=14+2x\)
\(\left|5x-3\right|=\frac{14+2x}{2}\)
\(\Rightarrow\orbr{\begin{cases}5x-3=\frac{-14-2x}{2}\\5x-3=\frac{14+2x}{2}\end{cases}}\)\(\Rightarrow\orbr{\begin{cases}\left(5x-3\right).2=-14-2x\\\left(5x-3\right).2=14+2x\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}10x-6+2x=-14\\10x-6-2x=14\end{cases}\Rightarrow\orbr{\begin{cases}12x=-14+6\\8x=14+6\end{cases}}}\Rightarrow\orbr{\begin{cases}12x=-8\\8x=20\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=\frac{-2}{3}\\x=2,5\end{cases}}\)
vậy \(\orbr{\begin{cases}x=\frac{-2}{3}\\x=2,5\end{cases}}\)
Những câu sau tương tự nhé.
Tìm x biết:
a) 2x-3 > 5x-4
b) -5x+6 < 1/3
c) 7-8x > 9/16
\(2x-3>5x-4\)
\(\Leftrightarrow2x-5x>-4+3\)
\(\Leftrightarrow-3x>-1\)
\(\Leftrightarrow x>\frac{1}{3}\)
\(-5x+6< \frac{1}{3}\)
\(\Leftrightarrow-5x< \frac{1}{3}-6\)
\(\Leftrightarrow-5x< \frac{1}{3}-\frac{18}{3}\)
\(\Leftrightarrow-5x< \frac{-17}{3}\)
\(\Leftrightarrow x< \frac{-17}{3}\div\left(-5\right)\)
\(\Leftrightarrow x< \frac{17}{15}\)
\(7-8x>\frac{9}{16}\)
\(\Leftrightarrow8x>7-\frac{9}{16}\)
\(\Leftrightarrow8x>\frac{112}{16}-\frac{9}{16}\)
\(\Leftrightarrow8x>\frac{103}{16}\)
\(\Leftrightarrow x>\frac{103}{16}\div8\)
\(\Leftrightarrow x>\frac{103}{124}\)
tìm x, biết:
A, x2 + 5x + 6 = 3x 34 + 2x -9
B, 2\(\sqrt{x}\)+ 8x + 5 = 5x - 4 + 3x + 19
C, 5\(\sqrt{x}\)+ 2x - 8 = 5x + 4 - 3x - 19