jawab yang mana saja kalo bisa semuanya please

1) akar2nya -1/4 dan 2/5
x² - (-1/4 + 2/5)x + (-1/4×2/5) = 0
x² - (-5/20 + 8/20)x + (-2/20) = 0
x² - (3/20)x - 2/20 = 0
------------------------------- × 20
20x² - 3x - 2 = 0

2)
1/p² + 1/q²
= q²/p²q² + p²/p²q²
= (p² + q²) / p²q²
= {(p + q)²- 2pq} / (pq)²
= {(-b/a)² - 2(c/a)} / (c/a)²
= {(-(-5/6)² - 2(-6/6)} / (-6/6)²
= {(5/6)² - 2(-1)} / (-1)²
= {(25/36) + 2}
= 25/36 + 72/36
= 97/36