\(-\dfrac{2}{3}\sqrt{\dfrac{\left(a-b\right)^3.b^5}{c}}.\dfrac{9}{4}\sqrt{\dfrac{c^3}{2\left(a-b\right)}}.\sqrt{98b}\)
\(-\dfrac{2}{3}\left(a-b\right)b^2.\sqrt{\dfrac{\left(a-b\right).b}{c}}.\dfrac{9}{4}.c\sqrt{\dfrac{c}{2\left(a-b\right)}}.7\sqrt{2b}\)
\(=-\dfrac{21}{2}\left(a-b\right)cb^3\)
−\(\dfrac{2}{3}\)\(\sqrt{\dfrac{\left(a-b\right)^2.b^5}{c}}\).\(\dfrac{9}{4}\) \(\sqrt{\dfrac{c^3}{2\left(a-b\right)}}\). \(\sqrt{98b}\)
= -\(\dfrac{2}{3}\) (a - b).b2.\(\sqrt{\dfrac{\left(a-b\right).b}{c}}\) .\(\dfrac{9}{4}\).c\(\sqrt{\dfrac{c^2}{2\left(a-b\right)}}\).7\(\sqrt{2b}\)
= -\(\dfrac{21}{2}\)(a-b).cb3