Question

Find the zeroes of the following quadratic polynomials and verify the
relationship between the zeroes and their coefficient.
1) 6x² -3-7x (2 marks)
2) 5n^2 - 25n (3 marks)​

Answer 1

Answer:

1. 6x^2 -3 -7x

Solution:

6x^2 -7x -3

= 6x^2- (9-2)x -3

=6x^2 - 9x +2x -3

=3x (2x -3) +1 (2x -3)

= (2x -3)(3x+1)

p (x) =0

(2x-3)(3x+1)=0

Either or

2x-3=0 3x+1=0

x=3/2 x= -1/3

Verification:

sum of the zeroes = -b/a

3/2+(-1/3)= - (-7)/6

9-2/6 = 7/6

7/6=7/6

Hence proved

2.5n^2 - 25n

Solution:

5n ( n - 5)

p (x)=0

5n (n-5)=0

Either or

5n=0 n-5=0

n=0 n=5

Verification:

sum of the zeroes = -b/a

0+5 = - (-25/5)

5=5

Hence proved