Question

write the value of a, b for the given quadratic equation x2+2x-9=0​

Answer 1

Factoring  x2+2x-9 

The first term is,  x2  its coefficient is  1 .

The middle term is,  +2x  its coefficient is  2 .

The last term, "the constant", is  -9 

Step-1 : Multiply the coefficient of the first term by the constant   1 • -9 = -9 

Step-2 : Find two factors of  -9  whose sum equals the coefficient of the middle term, which is   2 .

     -9   +   1   =   -8     -3   +   3   =   0     -1   +   9   =   8

Observation : No two such factors can be found !!

Conclusion : Trinomial can not be factored

Answer 2

$\huge\bf\pink{x^2+2x-9=0}$

Now ,

Comparing equation with $\bf\green{ax^2+bx+c=0}$ with $\bf\blue{x^2+2x-9=0}$

So,

$\huge\bf\star\pink{a=1}$

❥Because in a place of x there is no coefficient .

❥So we can take 1 as coefficient.

$\huge\bf\star\pink{b=2}$

$\huge\bf\star\pink{c=-9}$