## College Algebra (6th Edition)

20$\sqrt2$ - 5$\sqrt3$
3$\sqrt 8$ - $\sqrt 32$ + 3$\sqrt 72$ - $\sqrt 75$ =3$\sqrt( 2\times2\times2)$ - $\sqrt (4\times4\times2)$ + 3$\sqrt (6\times6\times2)$ - $\sqrt (5\times5\times3)$ =3$\sqrt{2^{2}\times2}$ - $\sqrt{4^{4}\times2}$ + 3$\sqrt{6^{6}\times2}$ - $\sqrt{5^{5}\times3}$ =3$\times2$$\sqrt2 - 4\sqrt2 + 3\times6$$\sqrt2$ - 5$\sqrt3$ =6$\sqrt2$ - 4$\sqrt2$ + 18$\sqrt2$ - 5$\sqrt3$ =(6-4+18)$\sqrt2$ - 5$\sqrt3$ =20$\sqrt2$ - 5$\sqrt3$