Question

find the zeroes of the following quadratic polynomials and verify the relationship between the zeroes and the coefficients 1)x²-7 2)3x²-9x 3) x²-x-90 please solve it fast

Answer 1

Got for 3rd

Hope this helps you

Answer 2

Step-by-step explanation:

1) x² - 7 = 0

 x² = 7

x =±√7

Sum of Zeros = √7 + -√7 = 0

Product of zeros = √7 * -√7 = -7

Now,

Sum of zeros = -b/a = 0

Product of zeros = c/a = -7

Hence verified.

2) 3x² - 9x = 0

   3x(x - 3) = 0

x = 0 or x = 3

Sum of zeros = 0+3 = 3

Product of zeros = 0*3 = 0

Now,

Sum of zeros = -b/a = - -9/3 = 3

Product of zeros = c/a = 0

Hence verified.

3) x² - x - 90 = 0

sum = -1 && product = -90

The numbers are -10,9

x² - 10x + 9x - 90 =  0

x(x-10) + 9(x-10) = 0

[x+9][x-10] = 0

x = -9 or x = 10

Sum of zeros = -9+10 = 1

Product of zeros = -9*10 = -90

Now,

Sum of zeros = -b/a = - -1/1 = 1

Product of zeros = -90/1 = -90

Hence verified