1)(m+5n)(m²-5mn+25n²)
2)x(y²-16x²)=x(y-4x)(y+4x)
3)-5(x²-6x+9)=-5*(x-3)²
4)7xy+14y-42x-84=7y(x+2)-42(x+2)=(x+2)(7y-42)=7(x+2)(y-6)
5)(100-c²)(100+c²)=(10-c)(10+c)(100+c²)
<span>2(b+1)²-4b = 2(b</span>² + 2b + 1<span>) - 4b = 2b</span>² +4b + 2 - 4b = 2b² + 2
An=a1+d(n-1)
46.5=-5.5+4(n-1)
52=4n-4
-4n=-56
n=14