Question

find the zeros of polynomial 2
x square - 9 x - 45 and verify the relationship between the zeros and the coefficients of the polynomial

Answer 1

2x^2-9x-45

S=-9

P=-90

-15,+6

= 2 x square + 6x - 15 x - 45

= 2 X ( X + 3) -15(x+3)

=( 2 x-15)( X + 3)

therefore the zeros are x=15/2and x =-3

x=15/ 2 is rejected

therefore X = -3

P(x) =2x^2 -9x -45

P(-3)=2(-3)^2 -9(-3) -45

=2(9) +27 -45

=18 +27 -45

=45 -45

P(-3)=o

therefore x = -3