=>4x^2-12x+9-4x^2-20x+x+5+17=0
=>-31x+31=0
=>x=1
=>4x^2-12x+9-4x^2-20x+x+5+17=0
=>-31x+31=0
=>x=1
tìm x biết:
a)x2 + 3x = 0 b) x3 – 4x = 0
c) 5x(x-1) = x-1 d) 2(x+5) - x2-5x = 0
e) 2x(x-5)-x(3+2x)=26 f) 5x.(x – 2012) – x + 2012 = 0
Tìm giá trị của biến số x để các phân thức sau bằng 0
a.2x-1/5x-10
b.x^2-x/2x
c.2x+3/4x-5
d.(x-1)(x+2)
e.(x-1)(x+2)/x^2-4x+3
BÀI 1.
CHỨNG MINH:
a) a^2(a+1)+2a(a+1) chia hết cho 6 vs a thuộc Z
b) a(2a-3)-2a(a+1) chia hết cho 5 vs a thuộc Z
BÀI 2.
a) 36x^2-49=0
b(x-1)(x+1)=x+2
c) x^2(x+1)+2x(x+1)=0
d) x(2x-3)-2(3-2x)=0
e) 2x^3(2x-3)-x^2(4x^2-6x+z)=0
f)(x-2)^2-(x+3)^2=5+4(x+1)
1) (x-1)2-9=0
2) (x-10)2-125=x(x-15)-5
3) (x+4)2-4x=(x-3)(x+3)-11
4) (2x-3)2+12x=(4x+3)(x-2)-5
Giúp em với ạ
giải các phương trình sau:
a)5-(x-6)=4(3-2x) b)\(\dfrac{3x+2}{2}-\dfrac{3x+1}{6}=2x+\dfrac{5}{3}\)
c)\(\dfrac{5x+2}{6}-\dfrac{8x-1}{3}=\dfrac{4x+2}{5}-5\) e)\(x-\dfrac{2x-5}{5}+\dfrac{x+8}{6}=7-\dfrac{x-1}{3}\)
d)x2-5x+6=0 f)(x2-4)-(x-2)(3-2x)=0 g)(2x+5)2=(x+2)2
RÚT GỌN BIỂU THỨC SAU:
a, 2x(x+3)-2(x+2)²
b, 2(x+2)(x-2)-(2x-3)(x-1)
c,(x+1)²-2(x²+6)-(x+1)(x-1)
d,(2x+1)²(2x+1)(x-1)+(x-1)²
e, 15xy²/27x²y
f,4xy³(x-2y)/12x²y(2y-x)²
g,20x-45/4x²+12x+9
h,(x-5)²-9/x²-4x+4
i,x40 +x^30+x^20+x^10+1/x^45+x^40+x^30+...+x^5+1
5,Thực hiện phép tính
1,\(\frac{3}{2x+6}-\frac{x-6}{2x^2+6x}\)
2,\(\frac{1}{1-x}+\frac{2x}{x^2-1}\)
3,\(\frac{1}{xy-x^2}-\frac{1}{y^2-xy}\)
4,\(\frac{5x+10}{4x-8}.\frac{4-2x}{x+2}\)
5,\(\frac{1-4x^2}{x^2+4x}:\frac{2-4x}{3x}\)
6,\(\frac{12x}{5y^3}.\frac{15y^4}{8x^3}\)
Câu 3. Giải các phương trình sau bằng cách đưa về dạng ax+b= 0
1. a, 3x-2=2x-3; b, 3-4y+24+6y=y+27+3y
c, 7-2x=22-3x; d, 8x-3=5x+12
e, x-12+4x=25+2x-1; f, x+2x+3x-19=3x+5
g, 11+8x-3=5x-3+x; h, 4-2x+15=9x+4-2
2. a, 5-(x-6)=4(3-2); b, 2x (x+2)2-8x2=2(x-2) (x2+2x-4)
c, 7-(2x+4)=-(x+4); d, (x-2)3+(3x-1) (3x+1)=(x+1)3
e, (x+1) (2x-3)=(2x-1) (x+5); f, (x-1)3-x(x+1)2=5x (2-x)-11 (x+2)
g, (x-1)-(2x-1)=9-x; h, (x-3) (x+4)-2(3x-2)=(x-4)2
i, x(x+3)2-3x=(x+2)3+1; j, (x+1) (x2-x+1)-2x=x(x+1) (x-1)
3. a, 1,2-(x-0,8)=-2(0,9+x); b, 3,6-0,5 (2x+1)=x-0,25 (2-4x)
c, 2,3x-2 (0,7+2x)= 3,6-1,7x; d, 0,1-2 (0,5t-0,1)=2 (t-2,5)-0,7
e, 3+2,25x+2,6= 2x+5+0,4x; f, 5x+3,48-2,35x= 5,38-2,9x+10,42
Bài 1: Giải các phương trình sau
a, \(\frac{4x-8}{2x^2+1}\)= 0
b, \(\frac{x^2-x-6}{x-3}\)= 0
c,\(\frac{x+5}{3x-6}\) - \(\frac{1}{2}\)= \(\frac{2x-3}{2x-4}\)
d,\(\frac{12}{1-9x^2}\)= \(\frac{1-3x}{1+3x}\) - \(\frac{1+3x}{1-3x}\)
e, \(\frac{x+5}{x-1}\)= \(\frac{x+1}{x-3}\) - \(\frac{8}{x^2-4x+3}\)
f, \(\frac{x+1}{x-2}\) - \(\frac{5}{x+2}\)= \(\frac{12}{x^2-4}\) + 1