If roots of the equation $x^2+ax-b=0$ are $3$ and $-7$ , find $a$ and $b$ ?

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Answer 1 · 2017-09-05T09:06:14

$a=4$ , $b=21$ and equation is $x^2+4x-21=0$

In an equation $px^2+qx+r=0$ , sum of roots (solutions) is $-q/p$ and product of roots is $r/p$ .

Hence in $x^2+ax-b=0$ , we have

$-a/1=3+(-7)=-4$

or $a=4$

and $-b/1=3xx(-7)=-21$

or $b=21$

and equation is $x^2+4x-21=0$

If roots of the equation x^2+ax-b=0x^2+ax-b=0 are 33 and -7-7, find aa and bb?