Respostas

2014-05-26T23:12:50-03:00
(2x-5) . (4x+1) +18x+5

(8x² + 2x - 20x - 5) + 18x+5
(8x²-18x-5+18x+5) + 18x+5
8x² - 18x + 18x - 5 + 5
         8x²
2014-05-26T23:18:13-03:00
(2x-5).(4x+1)+18x+5
8x²+2x-20x-5+18x+5
8x²+2x+18x-20x+5-5
8x²+20x-20x+0
8x²+0+0
8x²