1.
А) (2m-4)² = 4m²-16m+16
B) (15+2c)² = 225+60c+4c²
C) (c-3x)(c+3x) = c²-9x²
D) a²-(3a-c)² = a²-(9a²-6ac+c²) = a²-9a²+6ac-c² = -8a²+6ac-c²
2.
A) a²+4ab+4b² = (a+2b)²
B) 4m²-x² = (2m-x)(2m+x)
C) 5-125b² = 5(1-25b²)
3.
(x-7)(x+7)-(x-3)² = x²-49-(x²-6x+9) = x²-49-x²+6x-9 = 6x-58