1. (x-8)^2+(7-x)(x-9) 2. 25x^2 - 10x+2

1.  Упростим выражения (x - 8)^2 + (7 - x) * (x - 9).  

(x - 8)^2 + (7 - x) * (x - 9) = x^2 - 2 * x * 8 + 8^2 + 7 * x - 7 * 9 - x^2 + 9 * x = x^2 - 16 * x + 64 + 7 * x - 63 - x^2 + 9 * x = x^2 - 7 * x + 64 + 7 * x  - 63 = x^2 + 64 - 63 = x^2 + 1; 

2. 25 * x^2 - 10 * x + 2 = 5^2 * x^2 - 2 * 5 * x + 1 + 1 = (5 * x0^2 - 10 * x + 1 + 1 = (5 * x - 1)^2 + 1.