Respostas

2014-06-25T18:01:25-03:00
3 (x-5)²+3 (x-5)= 3(x-5)[(x-5) + 1], ou
........
3 (x-5)
²+3 (x-5) = 3(x²-10x+25)+3x-15 = 3x²-30x+75+3x-15 = 3x²-27x+60 = 3(x²-9x+20).