(5+b)^2-(b^2-2b+1) = 5^2+2*5*b+b^2-b^2+2b-1 = 25+10b+2b-1 = 12b+24
Если b=0,25, то 12b+24 = 12*0,25+24 = 3+24 = 27
(5+b)^2-(b^2-2b+1) = 5^2+2*5*b+b^2-b^2+2b-1 = 25+10b+2b-1 = 12b+24
Если b=0,25, то 12b+24 = 12*0,25+24 = 3+24 = 27