Bantu pliss buat besok,30 poin

3) 6y² – 9y – 4 = 0
a + b = -(-9)/6 = 3/2
a x b = -4/6 = -⅔

(a + b)² = a² + 2ab + b²
a² + b² = (a + b)² – 2ab
= (3/2)² – 2(-⅔)
= 9/4 + 4/3
= (27+16)/12
= 43/12
= 3 7/12

b/a + a/b = (b² + a²)/ab = (43/12) / -⅔
= 43/12 x (-3/2)
= -43/8
= -5 ⅜

(a – b)² = a² + b² – 2ab
= 43/12 – 2(-⅔)
= 43/12 + 4/3
= (43+16)/12
= 59/12
= 4 11/12