Question

Square root of 8 - square root of 9

Answer 1

`√(a)=b\iff b^2=a\qquad for\ a\geq0\ and\ b\geq0\\\\\sqrt8-\sqrt9=√(4\cdot2)-3=\sqrt4\cdot\sqrt2-3=\boxed{2\sqrt2-3}\\\\\sqrt9=3\ because\ 3^2=9\\\\\sqrt4=2\ because\ 2^2=4\\\\Used\ √(ab)=√(a)\cdot√(b)\\\\Answer:\ \boxed{\sqrt8-\sqrt9=2\sqrt2-3}`