Toán Lớp 8: Bài 2. Rút gọn biểu thức a/ (3x – 2)2 + 4(3x – 2) + 4 b/ (2x – 3)2 – (2x + 3)(2x – 3) c/ 5(2x– 1)2 + 4(x – 1)(x + 3) – 2(5 – 3x)2 d/

Question

Toán Lớp 8:  Bài 2. Rút gọn biểu thức a/ (3x – 2)2 + 4(3x – 2) + 4  b/ (2x – 3)2 – (2x + 3)(2x – 3) c/ 5(2x– 1)2 + 4(x – 1)(x + 3) – 2(5 – 3x)2  d/ (5x– 1)2 + (5x– 1)(5x+ 1) – 2(5x+ 2) (x– 1 ) e/ (2x– 3)2 + (2x+ 3)2 – 4(2x– 1) (x+ 1)  f/ (6x – 2)2 + (2 – 5x)2 + (12x – 4)(2 – 5x) MN GIÚP MIK VS , MIK CẦN GẤP. HỨA VOTE 5*.

thanhbinh2k5 · Answer

a)(3x-2)&sup2;+4(3x-2)+4   =(3x-2)&sup2;+2.(3x-2).2+2&sup2;   =(3x-2+2)&sup2;   =(3x)&sup2;   =9x&sup2;   b)(2x-3)&sup2;-(2x+3)(2x-3)   =(2x-3)[(2x-3)-(2x+3)]   =(2x-3)(2x-3-2x-3)   =(2x-3).(-6)   =-12x+18   c)5(2x-1)&sup2;+4(x-1)(x+3)-2(5-3x)&sup2;   =5(4x&sup2;-4x+1)+(4x-4)(x+3)-2(25-30x+9x&sup2;)   =20x&sup2;-20x+5+4x&sup2;+12x-4x-12-50+60x-18x&sup2;   =(20x&sup2;+4x&sup2;-18x&sup2;)+(-20x+12x-4x+60x)+(5-12-50)   =6x&sup2;+48x-57   d)(5x-1)&sup2;+(5x-1)(5x+1)-2(5x+2)(x-1)   =25x&sup2;-10x+1+25x&sup2;-1-2(5x&sup2;-5x+2x-2)   =25x&sup2;-10x+1+25x&sup2;-1-10x&sup2;+10x-4x+4   =(25x&sup2;+25x&sup2;-10x&sup2;)+(-10x+10x-4x)+(1-1+4)   =40x&sup2;-4x+4   e)(2x-3)&sup2;+(2x+3)&sup2;-4(2x-1)(x+1)   =4x&sup2;-12x+9+4x&sup2;+12x+9-4(2x&sup2;+2x-x-1)   =4x&sup2;-12x+9+4x&sup2;+12x+9-8x&sup2;-8x+4x+4   =(4x&sup2;+4x&sup2;-8x&sup2;)+(-12x+12x-8x+4x)+(9+9+4)   =-4x+22   f)(6x-2)&sup2;+(2-5x)&sup2;+(12x-4)(2-5x)   =(6x-2)&sup2;+2(6x-2)(2-5x)+(2-5x)&sup2;   =(6x-2+2-5x)&sup2;   =x&sup2;