Question

Срочно!!! Сократить дроби
1)
14а³
——
21а

2)
12а
——
-42а

3)
х²-49
———
6х+42

4)
12а²-6а
————
3-6а​

Answer 1

Объяснение:

1)

$\frac{14a {}^{3} }{21a} = \frac{2a {}^{2} }{3}$

2)

$\frac{12a}{ - 42a} = \frac{2}{ - 7} = - \frac{2}{7}$

3)

$\frac{ x {}^{2} - 49}{6x + 42} = \frac{(x - 7) \times (x + 7)}{6(x + 7)} = \frac{x - 7}{6}$

4)

$\frac{12a {}^{2} - 6a }{3 - 6a} = \frac{3(4a {}^{2} - 2a) }{3(1 - 2a)} = \frac{2a \times (2a - 1) }{ - (2a - 1) } = 2a \times ( - 1) = - 2a \times 1 = - 2a$