a) \(\Rightarrow3x\left(x-5\right)-2\left(x-5\right)=0\)
\(\Rightarrow\left(x-5\right)\left(3x-2\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x=5\\x=\dfrac{2}{3}\end{matrix}\right.\)
b) \(\Rightarrow x^3+6x^2+12x+8-x^3+6x^2=4\)
\(\Rightarrow12x^2+12x+4=0\)
\(\Rightarrow x\in\varnothing\)(do \(12x^2+12x+4=12\left(x^2+x+\dfrac{1}{4}\right)+1=12\left(x+\dfrac{1}{2}\right)^2+1\ge1>0\))
tìm x biết:
a) 4x2-(x-3)2=0
b)x2-4+(x+2)2=0
Bài 2: Tìm x, biết :
a) 3x^2-15x=0
b) 2x(x-3)+3-x=0
c) x^3-3x^2-6x-6+8=0
d) (x-2)^2-16(5-2x)^2
cảm ơn trước ạ
Tìm x, biết:
a)x(2x-3)-(2x-1)(x+5)=17
b)(2x+5)^2+(3x-10)^2+2.(2x+5)(3x-10)=0
Tìm x:
a) \(3x\left(3x-8\right)-9x^2+8=0\)
b)\(6x-15-x\left(5-2x\right)=0\)
c) \(x^3-16x=0\)
d) \(2x^2+3x-5=0\)
e) \(3x^2-x\left(3x-6\right)=36\)
f) \(\left(x+2\right)^2-\left(x-5\right)\left(x+1\right)=17\)
g) \(\left(x-4\right)^2-x\left(x+6\right)=9\)
h) \(4x\left(x-1000\right)-x+1000=0\)
i) \(x^2-36=0\)
j) \(x^2y-2+x+x^2-2y+xy=0\)
k) \(x\left(x+1\right)-\left(x-1\right).\left(2x-3\right)=0\)
l) \(3x^3-27x=0\)
1:
1). 2x-3=11-5x
2). 0,5(2x-9)=1,5x(x-5)
3). 28(x-1)-9(x-2)=14x
4). 8(3x-2)-14x=2(4-7x)+18x
5). 2(x-5)-6(1-2x)=3x+2
6). 2x-3=3(x-1)+x+2
1. Tính:
a) ( 3x+1) (3x-1) ; ( x+5y) (x-5y)
b) ( x-3) (x^2+3x+9) ; (x-5) (x^2+5x+25)
2. Rút gọn biểu thức:
a) (x+1) ^2 - (x-1)^2-3 (x+1) (x-1)
b) 5(x+2) (x-2) - (2x-3) ^2-x^2+17
c) (x-1) ^3-(x-1)(x^2+x+1)
d) (x-3) ^3-(x-3)(x^2+3x+9) +6(x+1) ^2
3. Tìm x:
a) (x+4) ^2-(x+1)(x-1) =16
b) (2x-1) ^2+(x+3) ^2-5(x+7) (x-7) = 0
c) (x-2) ^3-(x-4)(x^2+4x+16) +6(x+1) ^2=49
d) (x+2)(x^2-2x+4) -x(x^2+2) =15
Tìm x; biết:
f.x3 – 7x2 = – 6x g.(x + 1)(x + 2)(x + 4)(x + 5) = 4
h.(x2 – 0,5) : 2x – (3x – 1)2 : (3x – 1) = 0
i. (x + 3)(x2 – 3x + 9) – x(x – 2)(x + 2) = 15
Bài 1: Tính
a.(2x+3y)^2-(5x-y)^2
b(x+2/5)^2.(x-2/5)-(2x-y)^2
c.(x+1/4)^2-(2x-3)^3
Bài 2: Tính giá trị biểu thức bằng cách vận dụng hằng đẳng thức
A=x^3+3x^2+3x+6 với x=19
B=x^3-3x^2+3x với x=11
Tìm x biết:
a)(x-1)(x-3)=3
b)9x^2-(x-4)^2+0
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