Respostas

2014-04-06T20:35:31-03:00
(x+30).(x-30) = 700
x² - 30x + 30x - 900 = 700
x² = 1600
x = √1600
x = 40

Belezinha?
1 5 1
2014-04-06T20:39:31-03:00