Question

7 x elevado a 2 + 13 x - 2 = 0

Answer 1

7×+13×-2=0
49×+13×-2=0
62×-2=0
×=62÷2
×=31


Resposta correta 31

Answer 2

equação do segundo grau em que 
a=7;b=13;c=-2
Δ=b²-4ac
Δ=13²-4.7.(-2)
Δ=169+56
Δ=225

x=$\frac{-b+-√Δ}{2a}$
x=$\frac{-13+-√225}{2.7}$
x=$\frac{-13+-15}{14}$
x=$\left \{ {{=[tex]\frac{-13+15}{14}$=2/14=1/7} \atop {=$\frac{-13-15}{14}=-4}} \right.$