a) ( 3 + x ) ( x ^ 2 - 9 ) - ( x - 3 ) ( x ^ 2 + 3x + 9 )
b) ( x + 6 ) ^ 2 - 2 x ( x + 6 ) + ( x - 6 ) ( x +6 )
1.Thực hiện phép tính
a, (3x+x)(x^2-9) - (x - 3) (x^2 +3x+9)
b, (x+6)^2 - 2x(x+6) +(x-6)(x+6)
2. Tìm x, biết
(2x-1)^2 - (4x+1) ( x-3) = -3
Các bạn giúp mình với ạ. C.ơn nhiều !!
\(a,\left(3x+x\right)\left(x^2-9\right)-\left(x-3\right)\left(x^2+3x+9\right)\)
\(=4x\left(x^2-9\right)-x^3+27\)
\(=4x^3-36x-x^3+27\)
\(=3x^3-36x+27\)
\(\left(x+6\right)^2-2x.\left(x+6\right)+\left(x-6\right).\left(x+6\right)\)
\(=\left(x+6\right).\left(x+6-2x+x-6\right)\)
\(=\left(x+6\right).0\)
\(=0\)
Mình làm phần tiếp của bạn Phạm Tuấn Đạt nha .
b) \(\left(x+6\right)^2-2x\left(x+6\right)+\left(x-6\right)\left(x+6\right)\)
\(=x^2+12x+36-2x^2-12x+x^2-36\)
\(=0\)
2.
\(\left(2x-1\right)^2-\left(4x+1\right)\left(x-3\right)=-3\)
\(4x^2-4x+1-\left(4x^2-12x+x-3\right)=-3\)
\(4x^2-4x+1-4x^2+12x-x+3+3=0\)
\(7x+7=0\)
\(x=-1\)
a chứng minh rằng: \(\dfrac{x+3+2.\sqrt{x^2-9}}{2x-6+\sqrt{x^2-9}}=\dfrac{\sqrt{x^2-9}}{x-3}\)
b rút gọn biểu thức T = \(\dfrac{x^2+5x+6+x.\sqrt{9-x^2}}{3x-x^2+\left(x+2\right)\sqrt{9-x^2}}\)
Chủ đề 1: Thực hiện phép tính
1) (2x+3).(2x-3)-4x.(x+5)
2) 6/x2 - 9 + 5/x-3 + 1/x+3
3)5x.(x-3)+(x-2)2
4) 4x/x+2 - 3x/x-2 + 12x/ x2 - 4
5) x(x+2) - ( x-3)(x+3)
6) 1/3x-2 + -4/3+2 + 6-3x/9x2 - 4
7)2x.(3x-1)+(x+2)2
8) 6/x+3 - 6/x-3 + 9x+9/x2 - 9
9) (2x - 5)2 - x(4x-13)
10) x-1/x + 4/x+8 + 8/x2 + 8x
11) (2x+1)2 + (x-5)(x+5)-x(5x+7)
12) 6/x2-9 + 5/x-3 + 1/x+3
13) 6x(5x-2)+(2x+3)2
14) x/x-2 + -2/x-3 + x(1-x)/x2-9
15) (x-2)2-x(x+5)
16) 2/x+3 + 3/x-3 + -6/x2-9
17) 3x(x-3) + (3x-1)2
\(\left(2x+3\right)\left(2x-3\right)-4x\left(x+5\right)=4x^2-9-4x^2-20x=-20x-9\)
\(5x\left(x-3\right)+\left(x-2\right)^2=5x^2-15x+x^2-4x+4=6x^2-19x+4\)
\(x\left(x+2\right)-\left(x-3\right)\left(x+3\right)=x^2+2x-\left(x^2-9\right)=x^2+2x-x^2+9=2x+9\)
thực hiện phép tính
a, \(\dfrac{x^2}{3x+6}+\dfrac{4x+4}{3x+6}\)
b, \(\dfrac{x+3}{x}+\dfrac{x}{3-x}-\dfrac{9}{3x-x^2}\)
a: \(\dfrac{x^2}{3x+6}+\dfrac{4x+4}{3x+6}=\dfrac{x^2+4x+4}{3x+6}=\dfrac{x+2}{3}\)
b: \(\dfrac{x+3}{x}+\dfrac{x}{3-x}-\dfrac{9}{3x-x^2}\)
\(=\dfrac{x^2-9-x^2+9}{x\left(x-3\right)}\)
=0
Bài 1/ a)(3+x)(x^2-9)-(x-3)(x^2+3x+9)
b)(x+6)^2-2x(x+6)+(x-6)(x+6)
c)2x(x-3y)+3y(2x-5y)
Bài 2/a) 49x^2-1=0 b) (2x-1)^2-(4x+1)(x+3)=-3
Bài 3/ A=x^2+2y^2-2xy+4x-2y+12
Bài 1 :
a) (3+x)(x2-9)-(x-3)(x2+3x+9) = ( x-3)(x+3)2-(x-3)(x2+3x+9)
= (x-3) ( x2+6x+9 - (x2+3x+9)) = (x-3) . 3x = 3x(x-3)
Các câu còn lại mình sẽ gửi bạn sau nếu có thời gian
Nhấn đúng để ủng hộ mình :))
Rút gọn:
A=(x+3+2.(x^-9)^1/2):(2x-6+(x^2-9)^1/2
B=(x^2+5x+6+x.(9-x^2)^1/2):(3x-x^2+(x+2).(9-x^2)^1/2
Rút gọn:
A=(x+3+2.(x^-9)^1/2)/(2x-6+(x^2-9)^1/2
B=(x^2+5x+6+x.(9-x^2)^1/2)/(3x-x^2+(x+2).(9-x^2)^1/2
1 Tính
a) x(3x2-2x+5)
b) (\(\dfrac{1}{2}\)x+3) (2x2-4x+6)
c) 2x (x-3y)+3y(2x-5y)
d) (3+x) (x2-9)-(x-3) (x2+3x+9)
e) (x+6)2-2x(x+6)+(x-6)(x+6)
a: \(=3x^3-2x^2+5x\)
b: \(=x^3-2x^2+3x+6x^2-12x+18\)
\(=x^3+4x^2-9x+18\)
c: \(=2x^2-6xy+6xy-15y^2=2x^2-15y^2\)
d: \(=\left(x+3\right)\left(x^2-9\right)-x^3+27\)
\(=x^3-9x+3x^2-27-x^3+27=3x^2-9x\)
1,Tính
a,(3+x)(x^2-9)-(x-3)(x^2+3x+9)
b,(x+6)^2-2x(x+6)+(x-6)(x+6)
mk cần gấp giúp mk vs
a,(3+x)(x2-9)-(x-3)(x2+3x+9)
=(3x2-27+x3-9x)-(x3-27)
=3x2-27+x3-9x-x3+27
=3x2-9x
=3x(x-3)
b,(x+6)2-2x(x+6)+(x-6)(x+6)
=x2+12x+36-2x2-12x+x2-36
=0
a) \(\left(3+x\right)\left(x^2-9\right)-\left(x-3\right)\left(x^2+3x+9\right)\)
\(=\left(3x^2+x^3-27-9x\right)-\left(x^3-27\right)\)
\(=3x^2+x^3-27-9x-x^3+27\)
\(=3x^2-9x\)
b) \(\left(x+6\right)^2-2x\left(x+6\right)+\left(x-6\right)\left(x+6\right)\)
\(=\left(x^2+12x+36\right)-\left(2x^2+12x\right)+\left(x^2-36\right)\)
\(=x^2+12x+36-2x^2-12x+x^2-36\)
\(=0\)