Chapter 10 Counting Methods and Probability - 10.2 Use Combinations and the Binomial Theorem - 10.2 Exercises - Mixed Review - Page 697: 65

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The equation of the perpendicular bisector is: $$(x-a_1)^2+(y-b_1)^2=(x-a_2)^2+(y-b_2)^2$$ We have two points $A(9,-2)\\B(3,6)$ Substitute the given values: $$(x-9)^2+(y+2)^2=(x-3)^2+(y-6)^2\\x^2-18x+81+y^2+4y+4=x^2-6x+9+y^2-12y+36\\12x-16y-40=0\\3x-4y-10=0$$