1. 1)x²-4x+4 2)9m²+54mn+81n² 3)c²-64 4)25b²-4a²
2. 1). (10-a)(10+a) 2)(x+5)² 3)(6y-7)(6y+7) 4). (4a-3b)²
3. m²-1-m²+6m-9
4.(2x+5)(x-6)+2(3x+2)(3x-2)=5(2x+1)²+11
2x²-12x+5x-30+2(9x²-4)=5(4x²+4x+1)+11
2x²-12x+5x-30+18x²-8=20x²+20x+5+11
2x²-12x+5x+18x²-20x²-20x=30+8+5+11
-27x=54
x=54:(-27)
x=-2
5.(2b-1)² - (b+2)²=(2b-1-b-2)(2b-1+b+2)=(b-3)(3b+1)
6.(c+4)(c-4)(c²+16)-(c²-8)²=(c²-16)(c²+16)-c⁴+16c²-64=c⁴-256-c⁴+16c²-64=16c²-320=16*1/16-320=1-320=319
7. x²-8x+18=x²-8x+16+2=(x-4)²+2
(x-4)²> или =0
(х-4)²+2 >0