Question

Помогите решить дам 20 балов

Answer 1

a) (3m-n)(3m+n)-(3m-2n)(3m+2n) = 9m²-n² - (9m²-4n²) = 9m²-n²-9m²+4n²= 3n² = 3(-1 целая 1/3)² = 16/3 = 5целых 1/3

б) (2k-c)(2k+c)+(c-0.5k)(c+0.5k) = 4k²-c²+c²-0.25k² = 3.75k² = 3.75(0.4)² = 0.6