Đáp án:
Giải thích các bước giải:
a)3x^3 y^2 : x^2=3xy^2
b)(x^5 +4x^3-6x^2) :4x^2=x^5 : 4x^2 +4x^3 : 4x^2 -6x^2 :4x^2=(1/4)x^3+x+(3/2)
c)(x^3-8):(x^2+2x+4)=(x-2)(x^2+2x+4):(x^2+2x+4)=x-2
d)(3x^2-6x):(2-x)=3x(x-2):[-(x-2)]=-3x
e)[(x^3-1)+(2x^2-2x)]:(x^2+3x+1)=[(x-1)(x^2+x+1)+2x(x-1)]:(x^2+3x+1)
=(x-1)(x^2+3x+1):(x^2+3x+1)=x-1
bài 10 bạn tự làm đi mình cũng ko rõ
bài 11:
1)A=x^2-6x+11=(x-3)^2+2≥2
B=x^2-20x+101=(x-10)^2+1≥1
C=x^2-4xy+5y^2+10x-22y+28
=[(1/4)x^2-2.2.(1/4)xy+4y^2]+[(3/4)x^2+2.(√3/4)(20√3/3)x+(400/3)]+(y^2-2.1.11y+121)-(679/3)
=[(1/2)x-2y]^2+[(√3/4)x+(20√3/3)]^2+(y-11)^2-(697/3)≥-697/3
Bài 12:
A=4x-x^2+3=-(x^2-4x-3)=-[(x-2)^2-7]≤7
B=-x^2+6x-11=-(x^2-6x+11)=-[(x-3)^2+2]≤-2