a: =8x+10+15x-21-5x
=18x-11
b: =x^2-4x+4-(x^2+x-12)
=x^2-4x+4-x^2-x+12
=-5x+16
c: =x(x^2-4)-x^3+27
=x^3-8x-x^3+27
=27-8x
d: =x^3+3x^2+3x+1-5x^3-(x^3-12x^2+48x-64)
=-4x^3+3x^2+3x+1-x^3+12x^2-48x+64
=-5x^3+15x^2-45x+65
1. Rút Gọn
a) -5x (x-3).(2x+4)-(x+3)(x-3)+(5x-2)(3x+4)
b) (4x-1)x(3x+1)-5x^2x(x-3)-(x-4)x(x-5)-7(x^3-2x^2+x-1)
c) (5x-7)(x-9)-(3-x)(2-5x)-2x(x-4)
d)(5x-4)(x+5)-(x+1)(x^2-6)-5x+19
e)(9x^2-5)(x-3)-3x^2(3x+9)-(x-5)(x+4)-9x^3
g) (x-1)^2 - (x+2)^2
Thanks mn nhiều ạ
bài 1 rút gọn biểu thức
a) (2x-5)^2-4x(x+3)
b) (x-2)^3 -6(x+4)(x-4)-(x-2)(x^2+2x+4)
c)(x-1)^2-2(x-1)(x+2)+(x+2)^2+5(2x-3)
bài 2 rút gọn biểu thức
a)(2-3x)^2-5x(x-4)+4(x-1)
b)(3-x)(x^2+3x+9)+(x-3)^3
c)(x-4)^2(x+4)-(x-4)(x+4)^2+3(x^2-16)
Thu gọn biểu thức a)x^2-4x(3x-4)+7x-5 b)7x(x^2-5)-3x^2y(xy-6y^2) c)(5x+4)(2x-7) d)4x(2x-3)-5x(x-2)+x^2(3-x)
Rút gọn biểu thức:
a)(x+2)2 +x(x-4)
b)(x-3)2 -(x+3)(x-4)
c)(3x+1)2+3x(2-4x)
d)(2x-4y)2 -(2x-3)(2x-3y)
Mình cần gấp nha
1.Tìm x
a) (x - 5)(x + 5) - (x + 3)^2 + 3 (x - 2)^2 = (x + 1)^2 - (x + 4)(x - 4) +3x^2
b) (2x + 3)^2 + (x - 1)(x + 1) = 5 (x + 2)^2 - (x - 5)(x + 1) + (x + 4)^2
c) (-x + 5)(x - 2) + (x - 7)(x + 7) = (3x + 1)^2 - (3x - 2)(3x + 2)
d) (5x - 1)(x + 1) - 2(x - 3)^2 = (x + 2)(3x - 1) - (x + 4)^2 + (x^2 - x)
2.Rút gọn :
a) A= 3 (x - 1)^2 - (x + 1)^2 + 2(x - 3)(x + 3) - (2x + 3)^2 - (5 - 20x)
b) B= 5x (x - 7)(x + 7) - x (2x - 1)^2 - (x^3 + 4x^2 - 246x) - 175
c) C = -2x (3x + 2)^2 + (4x + 1)^2 + 2 (x^3 + 8x + 3x - 2 ) - (5 - x)
Bài 1: Rút gọn biểu thức
a. (6x+1).(x+2) - 2x.(3x-5)
b.(2x-1)2 - (2x-3).(2x+3)
c. (2x-3)3 - (3x+1) . (5-4x) - 16x2
d. (3x+2) - (x-5)- - x(3x - 13)
e. (5x+1).(x-2)-x.(5x-9)
g. x(x+3)2 -(x+2).(x2 - 2x+7) - 6x2
Bài 3: Rút gọn biểu thức: a) (a+1)^2-(a-1)^2-3(a+1)(a-1) b) (m^3-m+1)2+(m^2-3)^2-2(m^2-3)(m^3-m+1) Bài 4: Tìm x, biết: a) ( 5x +1)^2 – ( 5x +3)( 5x – 3) = 3 b) (3x-5)(5-3x)+9(x+1)^2=30 c) (x+4)^2-(x+1)(x-1)=16 Bài 5: So sánh hai số A và B: a) A=(3+1)(3^2+1)(3^4+1)(3^8+1)(3^(16)+1) và B=3^(32)-1 b) và A= 2011.2013 và B=2012^2 Bài 6: a) C/ m HĐT : (a+b+ c)^2 = a^2 +b^2 + c^2 +2ab +2ac + 2bc b)Áp dụng: cho x^2 + y^2 + z^2 = 5. Tính giá trị biểu thức: A = ( 2x + 2y – z)^2 + ( 2y + 2z – x)^2 + ( 2z+2x – 2y)^2 Bài 7: Cho 5x^2 + 5y^2 + 8xy - 2x + 2y +2 = 0 Tính giá trị biểu thức B = ( x + y ) ^2018 + ( x -2)^ 2019 + ( y +1)^2020
Bài 1:Thực hiện phép tính
a,(5-2x)(x+3)-4x(x+2) b,(3x+1)(x-3)-4(x+2)(x-2)
c,3(x-4)(x+3)+(x-5)(x+3) d,2x(x-4)+(3x-1)(2x-5)
Bài 2:Tìm x biết
a,5x(x+3)-(5x+2)(x+3)=7
b,(3x-1)(3x+2)-9(x+2)(x-2)=10
c,(x+1)(2x-5)+2(3-x)(x+2)=7
d,(1-3x)(x+2)+3x(x-5)=8
Bài 4: Tìm x, biết:
a) 3(2x – 3) + 2(2 – x) = –3 ; b) x(5 – 2x) + 2x(x – 1) = 13 ;
c) 5x(x – 1) – (x + 2)(5x – 7) = 6 ; d) 3x(2x + 3) – (2x + 5)(3x – 2) = 8 ;
e) 2(5x – 8) – 3(4x – 5) = 4(3x – 4) + 11; f) 2x(6x – 2x 2 ) + 3x 2 (x – 4) = 8.
bài 11.rút gọn biểu thức:
\(a,\dfrac{9x^2}{11y^2}:\dfrac{3x}{2y}:\dfrac{6x}{11y}\) \(b,\dfrac{3x+15y}{x^3-y^3}:\dfrac{x+5y}{x-y}\)
\(c,\dfrac{x^2-1}{x^2-4x+4}:\dfrac{x+1}{2-x}\) \(d,\dfrac{5x+10}{x+2}:\dfrac{5y}{x}\)
\(e,\dfrac{2x}{3x-3y}:\dfrac{x^2}{x-y}\) \(f,\dfrac{5x-3}{4x^2y}-\dfrac{x-3}{4x^2y}\)
\(g,\dfrac{3x+10}{x+3}-\dfrac{x+4}{x+3}\) \(h,\dfrac{4}{x-1}+\dfrac{2}{1-x}+\dfrac{x}{x-1}\)
\(i,\dfrac{2x^2-x}{x-1}+\dfrac{x+1}{1-x}+\dfrac{2-x^2}{x-1}\) \(j,\dfrac{x-2}{x-6}-\dfrac{x-18}{6-x}+\dfrac{x+2}{x-6}\)
\(k,\dfrac{x}{x^2-4}+\dfrac{2}{2-x}+\dfrac{1}{x+2}\) \(m,\dfrac{3}{2x+6}-\dfrac{x-6}{2x^2+6x}\)
\(n,\dfrac{3}{x+3}-\dfrac{x-6}{x^2+3x}\) \(p,\dfrac{x+3}{x}-\dfrac{x}{x-3}+\dfrac{9}{x^2-3x}\)
