HOC24
Lớp học
Môn học
Chủ đề / Chương
Bài học
Bài 1:
a.
2x(3x2−5x+3)=2x.3x2−2x.5x+2x.3=6x3−10x2+6x2x(3x2−5x+3)=2x.3x2−2x.5x+2x.3=6x3−10x2+6x
b.
−2x2(x2+5x−3)=−2x2.x2+(−2x2).5x+(−2x2)(−3)−2x2(x2+5x−3)=−2x2.x2+(−2x2).5x+(−2x2)(−3)
=−2x4−10x3+6x2=−2x4−10x3+6x2
c.
−12x2(2
a) 2x(3x2 - 5x +3 ) = 6x3 - 10x2 + 6x
b) -2x2 ( x2 + 5x - 3 ) = -2x4 - 10x3 + 6x2
c) - 1212x2 ( 2x3 - 4x +3 ) = -x5 + 1212x3 - 3232x2
d) ( 2x - 1 ) ( x2 + 5 - 4 ) = 2x3 + 10x - 8x - x2 - 5 + 4
= 2x3 - x2 + 2x -1
e) 7x (x -4 ) - ( 7x + 3 ) ( 2x2 - x + 4 )
= 7x2 - 28x - ( 14x3 - 7x2 + 28x + 6x2- 3x + 12 )
=7x2 - 28x - ( 14x3 - x2 + 25x + 12 )
= 7x2 - 28x - 14x3 + x2 - 25x - 12
=8x2 - 53x - 14x3 -12