1). (5-p)^2=25-10*p+p^2; 2).(4+k)^2=16+8*k+k^2.
Решение смотри на фотографии
115.
1) (3c+1 +c(c-1)) /(c-1) = (3c+1+c^2-c) /(c-1) =
=(c^2+2c+1) /(c-1) =(c+1)^2 /(c-1)
2) (c+1)^2 /(c-1) × 1/(c+1) =
=(c+1)^2 /(c-1)*(c+1) =(c+1) /(c-1)
- 3(x - 5) = 2(x + 3)
-3x + 15 = 2x + 6
- 3x - 2x = 6 - 15
- 5x = - 9
x = 9/5
x = 1,8