(c+6)^2 + 2c(3c-b) при c=3, b=корень5

Question

(c+6)^2 + 2c(3c-b) при c=3, b=корень5

Answer 1

C^2+12c+36+6c^2-2bc=7c^2+12c-2bc+36=7×9+36-6sqr (5)+36=144-6sqr (5)