find the equation of the tangent line to 9x^2+16y^2=52 through (2,-1). A. -9x+8y-26=0. B. 9x-8y-26=0. C. 9x-8y-106=0. D. 8x+9y-17=0. E. 9x+16y-2=0 . the slope is 9/8 idk where to go from there...