Question

If a+b=9 and ab= -22,find:
(i) a-b​

Answer 1

Refer to the image attached for solution.

Answer 2

$\huge \color{white} \fcolorbox{lime}{black}{\sf{ʂơƖųɬıơŋ}}$

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

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

$\implies \sf {9}^{2} - 4. - 22 \\ \\ \implies \sf1 + 88 = 169 \\ \\ \implies \sf \therefore \: a - b = \sqrt{169} = 13$

Hope it helps you...