2x+15=x+50
Tìm x
-15(x+2) + 7(2x-3) = 50
-15x - 30 + 14x - 21 -50 = 0
-15x + 14x = 50 + 21 + 30
-x = 101
x = -101
=> -15x+(-30)+14x-21=50
=>(15x-14x)-(30+21)=50
x-51=50
x=-101
Tìm x
a, 2x + (-35)=15
b, -15.(x+2)+7.(2.x-3) = -50
a,2x - 35 = 15
2x=50
x=25
Vậy x=25
b, -15(x+2) + 7(2x-3)= -50
-15x - 30 + 14x - 21 = -50
-x - 51 = -50
-x=1
x= -1
Vậy......
a) 2x+(-35)=15
2x=15-(-35)
2x=50
x=50:2
x=25
A. -15(x + 2) + 7(2x - 3)= -50
B. 3(x + 2) - 6(x - 5)= 2(5 - 2x)
a, \(-15\left(x+2\right)+7\left(2x-3\right)=-50\\ -15x-30+14x-21=-50\\ -x-51=-50\\ -x=-50+51\\ -x=1\\ \Rightarrow x=-1\)Vậy \(x=-1\)
b, \(3\left(x+2\right)-6\left(x-5\right)=2\left(5-2x\right)\\ 3x+6-6x+30=10-4x\\ -3x+36=10-4x\\ -3x+4x=10-36\\ x=-26\)Vậy \(x=-26\)
a, −15(x+2)+7(2x−3)=−50−15x−30+14x−21=−50−x−51=−50−x=−50+51−x=1⇒x=−1Vậy x=−1
b, 3(x+2)−6(x−5)=2(5−2x)3x+6−6x+30=10−4x−3x+36=10−4x−3x+4x=10−36x=−26Vậy
đề : tìm x ϵ , biết
a) x +39 +50
b) 2x -15 = 17
\(a,x+39=50\\ \Rightarrow x=11\\ b,2x-15=17\\ \Rightarrow2x=32\\ \Rightarrow x=16.\)
3/4(x-5)+15/50-2x^2=-7/6(x+5)
\(\dfrac{3}{4\left(x-5\right)}-\dfrac{15}{2\left(x-5\right)\left(x+5\right)}=\dfrac{-7}{6\left(x+5\right)}\)
\(\Leftrightarrow9\left(x+5\right)-90=-14\left(x-5\right)\)
=>9x+45-90=-14x+70
=>23x=70-45+90=115
hay x=5(loại)
a) 6x+5/3x+3=5-4x/1-2x
b) 3/4(x-5)+15/50-2x^2=-7/6(x+5)
\(ĐKXĐ:x\ne-1;x\ne\dfrac{1}{2}\)
Ta có : \(\dfrac{6x+5}{3x+3}=\dfrac{5-4x}{1-2x}\)
\(\Leftrightarrow\left(6x+5\right)\left(1-2x\right)=\left(5-4x\right)\left(3x+3\right)\)
\(\Leftrightarrow6x-12x^2+5-10x=15x+15-12x^2-12x\)
\(\Leftrightarrow5-4x-12x^2-15-3x+12x^2=0\)
\(\Leftrightarrow-10-7x=0\)
\(\Rightarrow x=\dfrac{-10}{7}\)
(-75):(x+6)=-15
B) -25-5×(x+2)=50
D, 6×(2x-8)-8×(3x-5)=-56
(-75) : (x + 6) = -15
x + 6 = -75 : (-15)
x + 6 = 5
x = 5 - 6
x = -1
B) -25 - 5.(x + 2) = 50
5(x + 2) = -25 - 50
5(x + 2) = -75
x + 2 = -75 : 5
x + 2 = - 15
x = -15 - 2
x = -17
D) 6.(2x - 8) - 8.(3x - 5) = -56
12x - 24 - 24x + 40 = -56
-12x + 16 = -56
-12x = -56 - 16
-12x = -72
x = (-72) : (-12)
x = 6
Lời giải:
a.
$-75:(x+6)=-15$
$x+6=(-75):(-15)=5$
$x=5-6=-1$
b.
$-25-5(x+2)=50$
$5(x+2)=-25-50=-75$
$x+2=-75:5=-15$
$x=-15-2=-17$
d.
$6(2x-8)-8(3x-5)=-56$
$(12x-48)-(24x-40)=-56$
$-12x-8=-56$
$-12x=-56+8=-48$
$x=(-48):(-12)=4$
(Đề ghi không rõ lắm, nên câu b có thể làm sai đề)
\(\dfrac{-75}{x+6}=-15\)
\(x+6=\dfrac{-75}{-15}=5\)
\(x=5-6=-1\)
\(-25-5x\left(x+2\right)=50\)
\(5x\left(x+2\right)=-25-50=-75\)
\(x\left(x+2\right)=x^2+2x=\dfrac{-75}{5}=-15\)
\(x^2+2x+1=-15+1=-14\)
\(\left(x+1\right)^2=-14\)
Suy ra không có nghiệm, vì không có căn bậc hai của số âm
1, -15(x+2)+7(2x-3)=-50
2, x^2-2x=0
3,(-2x)×(-4x)+28=100
1. => -15x-30+14x-21 = -50
=> -x-51 = -50
=> -x = -50 + 51 = 1
=> x = -1
2. = >x.(x-2) = 0
=> x=0 hoặc x-2=0
=> x=0 hoặc x=2
3. => 8x^2+28 = 100
=> 8x^2 = 100-28 = 72
=> x^2 = 72 : 8 = 9
=> x=3 hoặc x=-3
Tk mk nha
tìm x
1. 3x - 7 = 19
2. (2x+1) . (x-3)=0
3. 3x+2/4 +1=5x-1/3
4. x/15 + 1/2 - x/50 = 5/6
5. x4 - 2x3 + 3x2 - 2x + 1=0
\(1,3x-7=19\\ \Rightarrow3x=26\\ \Rightarrow x=\dfrac{26}{3}\\ 2,\left(2x+1\right)\left(x-3\right)=0\\ \Rightarrow\left[{}\begin{matrix}2x+1=0\\x-3=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=-\dfrac{1}{2}\\x=3\end{matrix}\right.\\ 3,3x+\dfrac{2}{4}+1=5x-\dfrac{1}{3}\\ \Rightarrow5x-\dfrac{1}{3}-3x-\dfrac{2}{4}-1=0\\ \Rightarrow2x-\dfrac{11}{6}=0\\ \Rightarrow2x=\dfrac{11}{6}\\ \Rightarrow x=\dfrac{11}{12}\)
\(4,\dfrac{x}{15}+\dfrac{1}{2}-\dfrac{x}{50}=\dfrac{5}{6}\\ \Rightarrow\dfrac{x}{15}-\dfrac{x}{50}=\dfrac{5}{6}-\dfrac{1}{2}\\ \Rightarrow x\left(\dfrac{1}{15}-\dfrac{1}{50}\right)=\dfrac{1}{3}\\ \Rightarrow\dfrac{7}{150}x=\dfrac{1}{3}\\ \Rightarrow x=\dfrac{50}{7}\)