If x = 9 in the equation √k+2−x=0 this equation becomes √k+2−9=0,which can be written as √k+2−9.Squaring each side of √k+2=9 gives k+2=81 or k=79 Substituting k = 79 into the equation √k+2−9=0 confirms this is the correct value for k. Choices A, B, and C are incorrect because substituting any of these values for k in the equation √k+2−9=0 gives a false statement. For example, if k=7, the equation becomes √7+2−9=√9−9=3−9=0,which is false.