Question

plssss....help with the first three questions some one

Answer 1

1 answer is 9xy

Is ur answer...

Answer 2

(1)

Given x + y + 3 = 0.

On cubing, we get

(x + y + 3)^3 = 0

x^3 + y^3 + 27 - 9xy = 0

x^3 + y^3 + 27 = 9xy.



(2).

Given f(x) = x^4 - a^2x^2 + 3a - a.

Since, x - a is a factor of f(x), then put f(a) = 0

f(a) = (a)^4 - a^2a^2 + 3a - a = 0

      = a^4 - a^4 + 3a - a = 0

      = 2a = 0

      a = 0.


Therefore the value of a = 0.



(3)

Given : a^2 + b^2 + c^2 = 30 and a + b + c = 10.

Now,

We know that (a + b + c)^2 = a^2 + b^2 + c^2 + 2ab + 2bc + 2ca

                        (10)^2  =  30 + 2(ab + bc + ca)

                        100 - 30 = 2(ab + bc + ca)

                        70 = 2(ab + bc + ca)

                        35 = ab + bc + ca.


Therefore ab + bc + ca = 35.


Hope this helps!