Ka mohon bantuannya no 19&20

19) x1 - x2 = (√D)/a
{√-5²-4(1)(4p-2)}/1 = 9
√(25-16p+8) = 9
√(33 - 16p) = 9
(33 - 16p) = 9²
33 - 16p = 81
33 - 81 = 16p
-48 = 16p
p = -48/16
p = -3
20) D = 0
b² - 4ac = 0
(2a-1)² - 4(a+1)(a+2) = 0
4a²-4a+1 - 4a²-12a-8 = 0
-16a - 7 = 0
-16a = 7
a = -7/16