Question

If a,b are the zeroes of polynomial f(x) = x²+5x+8 ,then a+b is

Answer 1

Answer :

The value of (a + b) is -5

Given :

• 'a' and 'b' are the zeroes if the polynomial x² + 5x + 8

To Find :

• The value of (a + b)

Concept to be used :

Relationship between the zeroes and the coefficients of the polynomial

$\sf \bullet \: \: Sum \: of \: the \: zeroes = -\dfrac{Coefficient \: of \: x}{Coefficient \: of \: x^{2}} \\\\ \sf \bullet \: \: Product \: of \: the \: zeroes = \dfrac{Constant \: term}{Coefficient \: of \: x^{2}}$

Solution :

The given quadratic equation is

$\sf x^{2} + 5x + 8$

From the relation of sum of the zeroes we have :

$\sf \implies a + b = -\dfrac{5}{1} \\\\ \sf \implies a + b = -5$

Thus , the value of (a + b) is -5

Answer 2

$\rule{200}3$

$\huge\tt{PROBLEM:}$

• If a,b are the zeroes of polynomial f(x) = x²+5x+8 ,then a+b is

$\rule{200}3$

$\huge\tt{CONCEPT~USED:}$

• Relationship between the zeros and coefficients of the polynomials is :

1. sum of zeros = (coefficient of x/coefficient of x²)
2. Product of zeroes = (constant term/coefficient of x²)

The quadratic equations is x² + 5x + 8

$\rule{200}3$

$\huge\tt{SOLUTION:}$

So, from the relations, we have -

→a + b = -5/1

→a + b = -5

Hence, the value of (a+b) is -5

$\rule{200}3$