tolong yang bisa ya jawab no 5 6 7 8

itu no 5,6,7,8

semoga membantu maaf telat lagi ngitung

5) (6a - 4) = 2 (3a - 2)

6) x^2 - 3x - 4 = (x + 1) (x - 4)

7) (5b + 15) / (2b^2 + 3b - 9)
= 5 (b + 3) / 2 (b + 6) (b - 3)
= 5 (b + 3) / (b + 3) (2b - 3)
= 5 / 2b - 3

8) (8x / x^2 + x - 20) - (8 / x - 4)
= (8 (x) /(x + 5)(x -4)) - (8 / x - 4)
= (8(x) / (x +5) (x -4)) - 8 (x + 5) / (x +5) (x -4) / (x +5) (x - 4)
= (8x - (8x + 40) / (x +5) (x -4)
= 40 / (x +5) (x -4)