a) ( 5x + 3) - ( x -1 ) = 0
\(\Leftrightarrow\)5x + 3 - x +1 =0
\(\Leftrightarrow\)4x +4 = 0
\(\Leftrightarrow\)4x = -4 \(\Leftrightarrow\)x = \(\frac{-4}{4}\) =-1
b) (3x -2 ) - ( 5x + 4) = ( x - 3) - ( x +5 )
\(\Leftrightarrow\)3x -2 - 5x -4 = x-3 - x -5
\(\Leftrightarrow\)3x - 5x - x + x = -3 -5 +2 +4
\(\Leftrightarrow\)-2x = -2 \(\Leftrightarrow\)x =\(\frac{-2}{-2}\)= 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
Tìm giá trị x, y, z:
a. (5x-2)(-1/3-2x)=0
b. x/2=y/3 với xy=54
c. x+2x+3x+4x+...+100x=-213
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) 5x-3 {4x-2 [4x-3(5x-2)]}=182
B1:tìm x biết a, (-2+x^2)(x^2-2)(x^2-2)(x^2-2)(x^2-2)=1 b, (2x+3)(x-4)+(x-5)(x-2)=(3x-5)(x-4) c,(8x-3)(3x+2)-(4x+7)(x+4)=(4x+1)(5x-1) d, 2x^2+3(x-1)(x+1)=5x(x+1) e, (8-5x)(x+2)+4(x-2)(x+1)=(2+x)(2-x) f, 4(x-1)(x+5)-(x+2)(x+5)=3(x-1)(x+2)
Bài 1: Rút gọn biểu thức sau:
a. 3x2(2x3- x+5) - 6x5-3x3+10x2
b. -2x(x3-3x2-xx+11)-2x4+3x3+2x2-22x2x
Bài 2: Chứng minh biểu thức sau không phụ thuộc vào x:
a. x(2x+1)-x2(x+2)+(x2-x+3)
b. 4(x-6)-x2(2+3x)+x(5x-4)+3x2(x-1)
Bài 3: Cho đa thức: f(x)=3x2-x+1
g(x)=x-1
a. Tính f(x).g(x)
b. Tìm x để f(x).g(x)+x2[1-3g(x)]=
Bài 4: Tìm x:
a. \(\dfrac{1}{4}\)x2-(\(\dfrac{1}{2}\)x-4)\(\dfrac{1}{2}\)x=-14
b. 2x(x-4)+3(x-4)+x(x-2)-5(x-2)=3x
(x-4)-5(x-4)
Các bạn giúp mik giải bt nha. Cảm ơn mn nhiêu ạ.
Tìm x
a) 6x(5x + 3) + 3x(1 – 10x) = 7 b) (3x – 3)(5 – 21x) + (7x + 4)(9x – 5) = 44
c) (x + 1)(x + 2)(x + 5) – x2(x + 8) = 27
d) 5x(12x + 7) – 3x(20x – 5) = - 100
e) 0,6x(x – 0,5) – 0,3x(2x + 1,3) = 0,138
Tìm x, biết :
|5x - 4| = |x + 2|
|2x - 3| - |3x + 2| = 0
|5/4. x - 7/2| - | 5/8. x + 3/5| = 0
|7x + 1| - |5x + 6| = 0
Tìm x trong tỉ lệ thức:
a)3/2x+3=5/3x-2
b)31-2x/x+23=9/4
c)3x+2/5x+7=3x-1/5x-3
d)x+3/8=2/x-3
TÌM X:
a) 5x-3=2x+1
b) 3.( x-5) - 5.(x+1)= 15
c) x-5/3 - x+2/5 = 1/2
d) 3x-7/2 = 5x-2/3
e) -2.(x-3) + 5.(x-1)= 3+x
f) x.(x-5)- x.(x-2)= 6-x
g) 1/3x-2=1/4x+4
