Question

18 and 19 answer please

Answer 1

Hey

Here is your answer,

19) ax^2 -6x -6=0

Product of zeroes= c/a
=-6/a

Given that,
Product of zeroes = 4
-6/a=4
a=-6/4
a=-3/2

18)If one of the zero is reciprocal of the other, 
let one zero be α
other zero will be 1/α

Product of roots = c/a
⇒ α × 1/α = 6a/(a²+9)
⇒ 1 = 6a/(a²+9)
⇒ a² + 9 = 6a
⇒ a² - 6a + 9 = 0
⇒ a² - 3a - 3a + 9= 0
⇒ a(a-3) -3(a-3) = 0
⇒ (a-3)(a-3) = 0
⇒ (a-3)²= 0
⇒ a = 3

Value of a is 3.

Hope it helps you!