\(\Leftrightarrow x^3-6x^2+12x-8+8x^3+12x^2+6x+1-9\left(x^3+3x^2+3x+1\right)=-16\)
\(\Leftrightarrow9x^3+6x^2+18x-7-9x^3-27x^2-27x-9=-16\)
\(\Leftrightarrow-21x^2-9x=0\)
\(\Leftrightarrow-3x\left(7x+3\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=-\dfrac{3}{7}\end{matrix}\right.\)
Bài Tìm x,biết
a) (x-1)^3+(2-x)(4+2x+x^2)+3x(x+2)=16
b) (x+2)(x2-2x+4)-x(x2-2)=16
c) x(x-5)(x+5)-(x+2)(x2-2x+4)=17
d)(x-3)3-(x-3)(x2+3x+9)+9(x+1)2=15
Tìm x sao cho: (x-2)3+(2x+1)3-9(x+1)3=-16
bài 1 tìm x
a) 4(18-5x)-12(3x-16)=15(2x-16)-6(x+14)
b) (x+3)(x+2)-(x-2)(x+5)=6
c) -x(x+3)+2=(4x+1)(x-1)+2x
d) (2x+3)(x-3)-(x-3)(x+1) = (2-x)(3x+1)+3
cần gấp mọi người giúp mình với
tìm x:
a.(x-3)^4-(x+3)^4+24x^3=216
b.(2x+1)(16x^4-8x^3+4x^2-2x+1)-(2x-1)(16x^4+8x^3+4x^2+2x+1)=2
tìm GTNN của bt:
x^2+2x+4
x^2-x-5/3/4
4x^2-x-3/16
tìm x biết
a) (2x+1)×(1-2x)+(2x - 1) ^2=22
b) (x-5)^2+(x-3)×(x+3)-2×(x+1)^2=0
c) (2x+3)^2+(2x -3)^2-2×(4x^2-9)=0
1) (x-1)³+3(x-3)²-(x+2)(x²-2x+4)=(x+2)³-(x-3)(x²+9)-6x²+5
2) (x-5)(x+5)-(x-2)³-7x²+(x+1)(x²-x+1)=(x+3)³-(x³+9x²)
3) (x-4)³-(x+5)(x²+5x+25)=(x+2)(x-2x+4)-(x+4)³-(x-7)
4) (x+1)³-(x+3)(x²-3x+9)=(x-3)³+3(2x+1)²-(x³-5x+1)
Bài 3: Rút gọn các biểu thức sau:
1) ( x+ 3)(x2 -3x + 9) - (x3 + 54)
2) (2x + y)(4x2 + 2xy + y2 ) - (2x – y)(4x2 + 2xy + y2 )
3) (x – 1)3 – (x + 2)(x2 -2x +4) +3(x +4)(x – 4)
4) x(x + 1)(x - 1) – (x + 1)(x2 – x +1)
5) 8x3 - 5 (2x + 1)(4x2 – 4x + 1)
6) 27 + (x – 3)(x2 +3x + 9)
7) (x – 1)3 – (x +2)(x2 -2x + 4) +3(x +4)(x -4)
8) (x – 2)3 +6( x – 1)2 –(x +1)(x2 -x +1) +3x
Sử dụng 7 hằng đẳng thức ở lớp 8 để tính:
a. (2x-3) (4x2 + 6x +9) - (2x+3) (4x2 - 6x +9)
b. (x+1) (x2 - x +1) - (x-1) (x2 +x +1)
c. (3x-1) (3x+1) - (3x-2)2
d. (2x - 3)2 - (2x +3) (2x-3)
e. (3x-4)2 - (2x+4)2
f. (3x - 5)3 - (3x+5)3
g. (2x-1)2 - (3x-1)2
h. (x-2y) (x2 +2xy + 4y2) + (x3 - 6y3)
1/rút gọn biểu thức
a)(x-4)^3 - 2x(x-5)^2 + (x-4)(x^2+4x+16)-(x-3)^3
b)(x+5)(x^2-5x+25)-(x+3)^3+(x-2)(x^2+2x+4)-(x-1)^3
c)(x+3y)^3 +(3x+2y)(9x^2-6xy+4y^2)-3(2x-y)^3
d)(3x+y)^3-(5x-y)(25x^2+5xy+y^2)+(x+2y)^3
cảm ơn mn ạ
