MK SẮP PHẢI NỘP RỒI HỨA VOTE 5*

Áp dụng công thức A²-B²=(A-B)(A+B) từ câu 28→ câu 40 ta có:

28.(7-2a+b)(7+2a-b)

29. (6a-3a+2b)(6a+3a-2b)= (3a+2b)(9a-2b)

30.( 9a-5a +3b)(9a+5a-3b)=(4a+3b)(14a-3b)

31. (a-2b-3a-b)(a-2b+3a+b)= (-2b-3b)(4a-b)

32.(5a-b-2a-3b)(5a-b+2a+3b)=(3a-4b)(7a+2b)

33.(4a+3b-b+2a)(4a+3b+b-2a)=(6a-2b)(2a+4b)=4(3a-b)(a+2b)

34.[2a-b-2(a-b)] [2a-b+2(a-b)]= (2a-b-2a+2b)(2a-b+2a-2b)=b(4a-3b)

35.[3(a+b)-2(a-2b)][3(a+b)+2(a-2b)]= (3a+3b-2a+4b) (3a+3b+2a-4b)= (a+7b) (5a-b)

36. [2(2a-b)-4(a-b)] [2(2a-b)+4(a-b)]= (4a-2b-4a+4b)(4a-2b+4a-4b)=2b(8a-6b)=4b(4a-3b)

37. [5(x-3)-(2x-7)] [5(x-3)+(2x-7)]= (5x-15-2x+7)(5x-15+2x-7)=(3x-8)(7x-22)

38.[7(x-5)-(x+4)] [7(x-5)+(x+4)]= (7x-35-x-4)(7x-35+x+4)=(6x-39)(8x-31)

39.[9(x+7)-(3x+8)] [9(x+7)+(3x+8)]= (9x+63-3x-8)(9x+63+3x+8)=(6x+55)(12x+71)

40. [6(x-y)-5(2x-1)] [6(x-y)+5(2x-1)]= (6x-6y-10x+5)(6x-6y+10x-5)=(-4x-6y+5)(16x-6y-5)

Áp dụng công thức A²+2AB+B²=(A+B)² ; A²-2AB+B²=(A-B)²

41.x²+10x+25=(x+5)²

42.x²+8x+16 =(x+4)²

43 x²+6x+9=(x+3)²

44. x²+14x+49=(x+7)²

45.x²+12x+36=(x+6)²

46. 4x²+12x+9= (2x+3)²

47. 9x²+12x+4= (3x+2)²

48. 16x²+8x+1= (4x+1)²

49. 4x^4 +20x²+25=(2x²+5)²

50.9x^4 +24x²+16= (3x²+4)²

51. 25x²-20xy+4y²= (5x-2)²

52. 4x²-12xy+9y²=(2x-3y)²

Xong rồi bạn nha, nếu thấy hay bạn cho mik 5 sao và CTLHN nha, chúc bạn học tốt!