a, 10x-x2-30
=-x2+10x-30
=-\([\)(x2-2.x.5+25)-25\(]\)-30
=-\([(\)x-5)2-25\(]\)-30
=(-5)2+25-30
=(x-5)-5
vậy....
b, -4x2-4x-5
=-(4x2-4x)-5
=-\([\)(4x2-2.x.2+4)-4\(]\)-5
=-\([\)(2x-2)2-4\(]\)-5
=-(2x-2)2+4-5
=-(2x-2)2-1
vậy.........
các bạn xem giúp với có đúng ko
1.(x+2)3+(x-3)2-x2(x+5)
2.(2x+3).(x-5)+2x(3-x)+x-10
3.(x+5).(x2-5x+25)-x(x-4)2+16x
4.(-x-2)3+(2x-4).(x2+2x+4)-x2.(x-6)
Bài 1: Thu gọn các biểu thức sau
a)(2x2 + 5x - 2)(2x2 - 4x +3)
b)(2x -3)(3x - 2) - 3x(2x - 5)
c)(x -1)(x2 + x + 1) - (x + 1)(x2 - x +1)
d)(x2 + x - 1)(x2 - x + 1)
e)(2 + 3y)2 - (2x -3y)2 -12xy
d)(x2 - 4x)(5 + 2x - x2)
cảm ơn!giúp mình với chiều nay ktra 15ph T_T
Tìm x :
1) ( 5x - 1 ) ( x + 1) - 2 ( x - 3 )2 = ( x + 2 ) ( 3x - 1 ) - ( x + 4 )2 + ( x2 - x )
2) ( 3x + 4 ) ( 3x - 4 ) - ( 2x + 5 )2 = ( x - 5 )2 + ( 2x + 1 )2 - ( x2 - 2x ) + ( x - 1 )2
3) ( x - 5 ) ( x + 5 ) - ( x - 2 )3 - 7x2 + ( x + 1 )( x2 - x + 1 ) = ( x + 3 )3 - ( x3 + 9x2 )
4) ( x - 6 )( x2 + 6x + 36 ) - ( x + 4 )3 = ( x - 2 )3 + ( x + 5 )( x2 - 10x + 25 ) - ( 2x3 + 6x2 )
5) ( 2x + 3 )3 - ( 2x + 5 )( 4x2 - 10x + 25 ) = ( 6x - 1 )2 - ( x - 2 )( x2 + 2x + 4 ) + x3
CÁC BẠN GIẢI NHANH CHO MÌNH NHA . BẠN NÀO GIẢI CHI TIẾT NHANH , ĐÚNG MÌNH TICK CHO.
1. khai triển HĐT :
(3x+4)^2=
(x-1)^2=
(x-3)^2=
(1/2x-5)^2 =
x^2-1=
x^2-y^2 =
x^2-2=
4x-1/9 =
3. viết cac biểu thức sau dươi dang HĐT
x^2 -2x+1
x^2 -10x +25
x^2+x +1/4
(2x-3) (2x+3)
(2/3x+5) (2/3x-5)
Tim x,y biet:
1)x^2-2x+5+y^2-4y=0
2)4x^2+y^2-20x+26-2y=0
3)x^2+4y^2+13-6x-8y=0
4)4x^2+4x-6y+9x^2+2=0
5)x^2+y^2+6x-10y+34=0
6)25x^2-10x+9y^2-12y+5=0
7)x^2+9y^2-10x-12y+29=0
89x^2+12x+4y62+8y+8=0
9)4x^2+9y^2+20x-6y+26=0
10)3x^2+3y^2+6x-12y+15=0
11)x^2+4y^2+4x-4y+5=0
12)4x^2-12x+y^2-4y+13=0
13)x^2+y^2+2x-6y+10=0
14)4x^2+9y^2-4x+6y+2=0
15)y^2+2y+5-12x+9x^2=0
16)x^2+26+6y+9y^2-10x=0
17)10-6x+12y+9x^2+4y^2=0
18)16x^2+5+8x-4y+y^2=0
19)x^2+9y^2+4x+6y+5=0
20)5+9x^2+9y^2+6y-12x=0
21)x^2+20+9y62+8x-12y=0
22)x^2=4y+4y^2+26-10x=0
23)4y^2+34-10x+12y+x^2=0
24)-10x+y^2-8y+x^2+41=0
25)x^2+9y^2-12y+29-10x=0
26)9x^2+4y^2+4y+5-12x=0
27)4y^2-12x+12y+9x^2=13=0
28)4x^2+25-12x-8y+y^2=0
29)x62+17+4y^2+8x+4y=0
30)4y^2+12y+25+8x+x^2=0
31)x^2+20+9y^2+8x-12y=0
giup mk voi minh can gap ak, cam on cac ban
Tìm x
a) ( 2x + 1 )2- 4x2 + 2x2 - 2 = 0
b) ( x - 2 ) . ( x + 2 ) - ( x + 3 )2 - 2x - 5 = 0
Giúp mình với ;-;
Tìm x
a,(7x+4)^2-(7x+4)(7x-4)=0
b, 5( x + 3 )( x - 3 ) + ( 2x + 3 )^2+(x-6)^=10
c, (x + 1)^3 + (x – 2)^3 – 2x^2 (x – 1,5) = 3
d,( x + 2)(x^2 – 2x + 4)(x – 2)(x^2 + 2x + 4) = – 65
e, 4x^2 + 4x – 5 = 2
f,16x^2 – 9(x + 1)^2 = 0
Các bạn giúp mình vs mai mình phải nộp rùii
1.(x+2)3+(x-3)2-x2(x+5)
2.(2x+3).(x-5)+2x(3-x)+x-10
3.(-x-2)3+(2x-4).(x2+2x+4)-x2.(x-6)