d) Cho H(x) = 0
3x2 + 2 - 7x = 0
3x2 - 7x +2 = 0
3x2 - 6x - x +2 = 0
3x(x - 2) - (x - 2) = 0
(x - 2)(3x - 1) = 0
x = 2 hoặc x = 1/3
5) Cho H(x) = 0
7x - 6x2 - 2 = 0
6x2 - 7x + 2 = 0
6x2 - 3x - 4x + 2 = 0
3x(2x - 1) - 2(2x - 1) = 0
(2x - 1) (3x - 2) = 0
x = 1/2 hoặc x = 2/3
6) Cho H(x) = 0
7x - 3x2 - 2 = 0
3x2 - 7x + 2 = 0
E nhầm giúp e bài 7 vs:))))))
bằng 23938ha92 nha
Bài 7:
a) H(x) = 3x2 + x - 4
Cho H(x) = 0
=> 3x2 + x - 4 = 0
3x2 -3x + 4x - 4 = 0
3x(x -1) + 4(x - 1) =0
(x - 1)(3x + 4) = 0
x = 1 hoặc x = - 4/3
b) Cho H(x) = 0
3 + 7x + 2x2 = 0
3 + 6x + x + 2x2 = 0
3(1 + 2x) + x(1 + 2x) = 0
(1 + 2x)(3 + x) = 0
x = - 1/2 hoặc x = -3
c) Cho H(x) = 0
4 + 3x2 - 8x = 0
3x2 - 8x + 4 = 0
3x2 - 6x - 2x + 4 = 0
3x(x - 2) - 2(x - 2) = 0
(x - 2)(3x - 2) = 0
x = 2 hoặc x = 2/3