Question

if 1 and - 3 are zeroes of the polynomial p(x) =x power of x is 3 - ax square - 13x + b find the value of a and b

Answer 1

# here is your answer//

p(x) = 0

x³-ax²-13x+b = 0

(1)³-a(1)²-13(1)+b = 0

1-a(1)-13+b = 0

1-a-13+b = 0

-12-a+b = 0

-a+b = 12__________(1)

p(x) = 0

x³-ax²-13x+b = 0

(-3)³-a(-3)²-13(-3)+b = 0

-27-a(9)-39+b = 0

-27-39-9a+b = 0

-66-9a+b = 0

-9a+b = 66________(2)

from equation (1) and (2)
-a + b = 12
-9a + b = 66
(+). (-). (-)
__________
8a + 0 = -54
8a = -54
a = -54/8-
////// a = -27/4 //////

fill a value in any equation
-a + b = 12

-(-27/4)+b = 12

27/4+b = 12

b = 12-(27/4)

b = 48-27/4

////// b = 21/4 //////

so a = -27/4 and b = 21/4

//hope it is helpful #R//☺☺