What is the answer please

Suppose a man is heterozygous for heterochromia, an autosomal dominant disorder which causes two different‑colored eyes in an individual, produced 25‑offspring with his normal‑eyed wife. of their children, 15 were heterochromatic and 10 were‑normal. calculate the chi‑square value for this observation.

X-intercept=-5 y-intercept=2 the equation of the line is

How do you solving the solution of each system using elimination?