The tangent equation of a point P (- - 3,4) over a circle X & # 178; + Y & # 178; = 25 is I found that my answer is different from the answer. I don't know which one is wrong. So I need a process answer, please

The tangent equation of a point P (- - 3,4) over a circle X & # 178; + Y & # 178; = 25 is I found that my answer is different from the answer. I don't know which one is wrong. So I need a process answer, please

Circle X & # 178; + Y & # 178; = 25, point P (- 3,4) is on the circle
The slope of OP is (4-0) / (- 3-0) = - 4 / 3
The tangent of the circle at point P is perpendicular to Op
The tangent slope k = - 1 / Kop = 3 / 4
The tangent equation is y-4 = 3 / 4 (x + 3)
That is, 3x-4y + 25 = 0