plss tolong banget isiin ini yah

4. x² - (x1+x2)x + x1.x2 = 0
x1+x2 = 3x1 + 1 + 3x2 + 1
= 3x1 + 3x2 + 2
= 3(x1 + x2) + 2
= 3(-b/a) + 2
= 3(-(-1)/3) + 2 = 1+2 = 3
x1.x2 = (3x1 + 1)(3x2 + 1)
= 9x1.x2 + 6(x1+x2) + 1
= 9(c/a) + 6(-b/a) + 1
= 9(-5/3) + 6(-(-1)/3) + 1
= -15 + 2 + 1
= -12
x² - 3x - 12 = 0

5. kebalikan maka akar2nya 1/x1 dan 1/x2
1/x1 + 1/x2 = 2
(x1+x2)/(x1.x2) = 2
(-b/a)/(c/a) = 2
-b/c = 2
-(3p-2)/-8 = 2
(3p - 2)/8 = 2
3p - 2 = 2(8)
3p = 16 + 2
p = 18/3 = 6
2p - 1 = 2(6) - 1 = 11