tim x
-1/6-x=5/12+-2/3
Tim x
(-15/12)+x+(3/7)=(6/5).x-(1/2)
\(-\frac{15}{12}+x+\frac{3}{7}=\frac{6}{5}x-\frac{1}{2}\)
<=>\(x-\frac{6}{5}x=-\frac{1}{2}+\frac{15}{12}-\frac{3}{7}\)
<=>\(-\frac{1}{5}x=\frac{9}{28}\)
<=>\(x=\frac{9}{28}:\left(-\frac{1}{5}\right)\)
<=>\(x=-\frac{45}{28}\)
1)a)2x-13=25+6x
b)12-x=3x+6
c)40-(25-2x)=x
d)|x-3|=5
e)|x-3|+(x+2)+(x+1)=12
2)tính
a)(-1).(-2).(-3).(-4).(-5).[(-3)-(-5)]
b)1-2+3-4+5-6+...-98+99
3)tim x
a)(x-1).(y-2)=5
b)x.(y-3)=12
1 )Tim x, y thuoc Z
x + y = x.y
2) Tim x thuoc Z
(x + 1)+(x+3)+(x+5)+...+(x+99)=0(x-3)+(x-2)+(x-1)+...+10+11=11-12(x-5)+7(3-x)=530(x+2)-6(x-5)-24x=100x + y = x.y
=> xy - x - y = 0
=> (xy - x) - y + 1 = 1
=> x(y - 1) - (y - 1) = 1
=> (x - 1)(y - 1) = 1
=> x - 1 = y - 1 = 1 hoặc x - 1 = y - 1 = -1
=> x = y = 2 hoặc x = y = 0
tim x
a)0,25x - 2/3x = -1 1/6
b)3/4 + 1/4.x +x - 7/6 .x = 5/12
\(a,0.25x\) - \(\frac{2}{3}x\) =\(1\frac{1}{6}\)
\(\Rightarrow x\cdot\left(0.25-\frac{2}{3}\right)=1\frac{1}{6}\)
\(\Rightarrow x\cdot\frac{-5}{12}=\frac{7}{6}\)
\(\Rightarrow x=\frac{7}{6}:\frac{-5}{12}\)
\(\Rightarrow x=\frac{-14}{5}=-2.8\)
2*x+1/2*x+6*x+1/6*x+12*x+1/12*x+20*x+1/20*x=5.Tim x
1)a)2x-13=25+6x
b)12-x=3x+6
c)40-(25-2x)=x
d)|x-3|=5
e)|x-3|+(x+2)+(x+1)=12
2)tính
a)(-1).(-2).(-3).(-4).(-5).[(-3)-(-5)]
b)1-2+3-4+5-6+...-98+99
3)tim x
a)(x-1).(y-2)=5
b)x.(y-3)=12
giải thưởng 5 BẠN ĐẦU TIÊN NHẬN TICK
_Mấy bác cứ thik đăng nhiều :v , nhìn mak ko muốn lm . E lm bài 1 thôi :v còn các bài còn lại bác tự lm ( nó cx dễ thôi mà ) _
Bài 1 :
\(a) 2x-13=25+6x\)
\(\Rightarrow2x-6x=25+13\)
\(\Rightarrow-4x=38\)
\(\Rightarrow x=-\dfrac{19}{2}\)
Vậy .......
\(b) 12-x=3x+6\)
\(\Rightarrow-x-3x=6-12\)
\(\Rightarrow-4x=-6\)
\(\Rightarrow x=\dfrac{3}{2}\)
Vậy .....
\(c) 40-(25-2x)=x\)
\(\Rightarrow40-25+2x=x\)
\(\Rightarrow15+2x=x\)
\(\Rightarrow2x-x=-15\)
\(\Rightarrow x=-15\)
Vậy ......
\(d) |x-3|=5\)
\(\Rightarrow\left[{}\begin{matrix}x-3=5\\x-3=-5\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=8\\x=-2\end{matrix}\right.\)
Vậy ....
e) \(|x-3|+(x+2)+(x+1)=12\)
\(\Rightarrow\left|x-3\right|+x+2+x+1=12\)
\(\Rightarrow\left|x-3\right|+2x+3=12\)
\(\Rightarrow\left|x-13\right|+2x=9\)
\(\Rightarrow\left[{}\begin{matrix}x-3+2x=9\\-\left(x-3\right)+2x=9\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=4\\x=6\end{matrix}\right.\) \(( x = 6 \) ko thỏa mãn điều kiện )
Vậy ....
1) Tim x biet :
a) - 12 (x - 5) + 7 . (3 - x) = 5
b) 30 . (x + 2) - 6 . (x - 5) - 24x = 100
2)tính
a)(-1).(-2).(-3).(-4).(-5).[(-3)-(-5)]
b)1-2+3-4+5-6+...-98+99
3)tim x
a)(x-1).(y-2)=5
b)x.(y-3)=12
Bài 2:
a: \(\left(-1\right)\cdot\left(-2\right)\cdot\left(-3\right)\cdot\left(-4\right)\cdot\left(-5\right)\cdot\left[\left(-3\right)-\left(-5\right)\right]\)
\(=-\left(1\cdot2\cdot3\cdot4\cdot5\right)\cdot\left[-3+5\right]\)
\(=-120\cdot2=-240\)
b: \(1-2+3-4+5-6+...-98+99\)
=(-1)+(-1)+...+(-1)+99
=99-49=50
Tim x:
a) 6 x X - 5 = 613 b) 12 x X + 3 x X = 30
C) 125 - 25 x (X - 1) = 100 d) ( X - 2 ) x 9 X - 4) = 0
`#040911`
`a)`
`6 \times x - 5 = 613`
`=> 6 \times x = 613 + 5`
`=> 6 \times x = 618`
`=> x = 618 \div 6`
`=> x = 103`
Vậy, `x = 103`
`b)`
`12 \times x + 3 \times x = 30`
`=> x \times (12 + 3) = 30`
`=> x \times 15 = 30`
`=> x = 30 \div 15`
`=> x = 2`
Vậy, `x = 2`
`c)`
`125 - 25 \times (x - 1) = 100`
`=> 25 \times (x - 1) = 125 - 100`
`=> 25 \times (x - 1) = 25`
`=> x - 1 = 25 \div 25`
`=> x - 1 = 1`
`=> x = 1 + 1`
`=> x = 2`
Vậy, `x = 2`
`d)`
`(x - 2) \times (9x - 4) = 0?`
`=>`
TH1: `x - 2 = 0`
`=> x = 0 + 2`
`=> x = 2`
TH2: `9x - 4 = 0`
`=> 9x = 4`
`=> x = 4/9`
Vậy, `x \in {2; 4/9}.`
\(a,6x-5=613\\ \Leftrightarrow6x=618\\ \Leftrightarrow x=103\\ b,12x+3x=30\\ \Leftrightarrow15x=30\\ \Leftrightarrow x=2\\ c,125-25\left(x-1\right)=100\\ \Leftrightarrow25\left(x-1\right)=25\\ \Leftrightarrow x-1=1\\ \Leftrightarrow x=2\\ d,\left(x-2\right)\cdot\left(9x-4\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=2\\x=\dfrac{4}{9}\end{matrix}\right.\)