№1. 1) 511*52/510 = 510*5*52/510 = 510*5*52/510 = 5*52 = 5*25 = 125
2) 166/47*64 = 412/47*43 = 410*42/410 = 410*42/410 = 42 = 16
№2. 1) m2-9n2 = (m-3n)*(m+3n)
2) 25x2-10xy+y2 = (5x-y)*(5x-y) = (5x-y)2
3) 125x3+y3 = (5x+y)*(25x2-10xy+y2)
№3. (x+1)2 - (x-2)*(x+2) = 7
x2+2x+1 - (x2-4) = 7
x2+2x+1 - x2 + 4 = 7
x2 + 2x + 1 - x2 + 4 = 7
2x+5 = 7
2x = 7 - 5
2x=2
x=1
