Question

(√18 + √288) -(√98 + √200)= ? 

Answer 1

(3√2+12√2)-(7√2+10√2)
15√2-17√2=-2√2

Answer 2

√18  = $\sqrt{9*2} =3* \sqrt{2}$
√288 = $\sqrt{144 * 2} = 12 \sqrt{2}$
√98  =$\sqrt{49*2} =7* \sqrt{2}$
√200 = $\sqrt{100*2} =10 * \sqrt{2}$
(3* $\sqrt{2}$ + 12 * $\sqrt{2}$ )- (7*  $\sqrt{2$ + 10 * $\sqrt{2}$)
=$15 \sqrt{2} -17 \sqrt{2} =-2 \sqrt{2}$