Chapter 10 - Radical Expressions and Equations - 10-4 Solving Radical Equations - Standardized Test Prep - Page 625: 53

D

$\sqrt {c^2-17}=8$ $(\sqrt {c^2-17})^2=8^2$ $c^2-17=64$ $c^2-17+17=64+17$ $c^2 = 81$ $\sqrt {c^2} = \sqrt {81}$ $c= 9, -9$ $\sqrt {c^2-17}=8$ $\sqrt {(-9)^2-17}=8$ $\sqrt {81-17}=8$ $\sqrt {64} = 8$ $8=8$ $\sqrt {c^2-17}=8$ $\sqrt {(-9)^2-17}=8$ $\sqrt {81-17}=8$ $\sqrt {64} = 8$ $8=8$ $\sqrt {c^2-17}=8$ $\sqrt {(9)^2-17}=8$ $\sqrt {81-17}=8$ $\sqrt {64} = 8$ $8=8$