Let K1 denote the region of R2 bounded by the ellipse with equation 9(x−9)2+16(y−9)2=1, and let K2 denote the region bounded by the ellipse with equation 16(x+1)2+9(y+3)2=1. There is a unique line ℓ which simultaneously bisects K1 and K2 into two pieces of equal area.
What is the y-intercept of ℓ?