1. (x-8)^2+(7-x)(x-9) 2. 25x^2 - 10x+2
1) (х-8)^2 = х^2 - 16х + 64 (7-х)(х-9)= 7х-63-х^2+9х =16х-63-х^2 х^2-16х+64+16х-63-х^2= 64-63=1