Đáp án:
a, x = 13/19
b, x = 3
c, x = 1/5
d, x = 1/33
Giải thích các bước giải:
a, (3x - 1)(x + 3) = (2 - x)(5 - 3x)
<=> 3x² + 8x - 3 = 3x² - 11x + 10
<=> 3x² + 8x - 3x² + 11x = 10 + 3
<=> 19x = 13
<=> x = 13/19
b, (x + 1)(x + 9) = (x + 3)(x + 5)
<=> x² + 10x + 9 = x² + 8x + 15
<=> x² + 10x - x² - 8x = 15 - 9
<=> 2x = 6
<=> x = 3
c, (x + 5)(2x - 1) = (2x - 3)(x + 1)
<=> 2x² + 9x - 5 = 2x² - x - 3
<=> 2x² + 9x - 2x² + x = - 3 + 5
<=> 10x = 2
<=> x = 1/5
d, (3x + 5)(2x + 1) = (6x - 2)(x - 3)
<=> 6x² + 13x + 5 = 6x² - 20x + 6
<=> 6x² + 13x - 6x² + 20x = 6 - 5
<=> 33x = 1
<=> x = 1/33
