tolong di jwab yah pliss besok di kumpul lengkap dengan cara kerjanya yah no 15 smpai 20

jawab

15.
ho =  2
r = 3/4
h1 = 2 x 3/4 = 3/2

panjang lintas = ho+  [ 2( h1) /(1 - r) ]
p = 2  +  [2 (3/2) /(1 - 3/4)]
p = 2 + [ 3/(1/4]
p = 2 + 12
p= 14 m

16.  x² -6x - 3 = 0
x1 + x2 = -b/a = 6
x1 x2 = c/a = -3

1/x1 + 1/x2 = (x1 + x2)/(x1 x2) = (6)/(-3)= - 2

17. x1= 4 , x2 = 6
x² - (4 +6) x + (4 .6) = 0
x² - 10x  + 24  = 0

18. x² + 3x - 7 = 0
x1  + x2 = - 3
x1 x2 = - 7

x1² x2 + x1 x2² = (x1 x2)(x1 + x2) = - 7 (-3) = 21