Question

if a+b=9 and ab=-22 find a-b

Answer 1

$given$

a+b=9

ab=-22

we know that

$(a - b) {}^{2} = (a + b) {}^{2} - 4ab$

so a-b =

$\sqrt{81 - ( - 88)}$

a-b=

$\sqrt{169 = 13}$