Respostas

2014-05-25T20:48:19-03:00
2014-05-25T20:57:09-03:00
2X²+7X+5=0
 A=2 B=7 C=5
Δ=B²-4ac
Δ=7²-4×2×5
Δ=49-40
Δ=9
[b +ou - √Δ] ÷2
√5÷2=[7-3]÷2=2
         [7+3]÷2=5