СРОЧНО НАДО ЗАВТРА СДАВАТЬ!!!!
1) = 25a^2 + 30a + 9 2) = x^2 - 12x + 36 3) = (a - 3)^2 4) = (x + 9)^2 5) = x^2 - 25 6) = 25y^2 - x^2 8) = (7a - 10) (7a + 10) 9) = y^2 + 4x^2 - y^2 = 4x^2