Question

1)Resolva as equações incompletas usando a formula de bhaskara.
a)25x² +70x=0
b)x² -7x+0
c)x² -1=0
d)x² +x=0

Answer 1

a)25x²+70x=0 
$\frac{-70+- \sqrt{70^2-4*25*0} }{2*25} = \frac{-70+-70}{50}$
x1= 0
x=-140/50= 14/5

b)x²-7x+0
$\frac{7+- \sqrt{(-7)^2-4*1*0} }{2*1} = \frac{7+-7}{2}$
x1=14/2= 7
x2=0

c)x²-1=0
$\frac{0+- \sqrt{0-4*1*(-1)} }{2*1} = \frac{\sqrt{4} } {2} = \frac{2}{2} =1$


d)x²+x=0
$\frac{-1+- \sqrt{1^2-0} }{2*1} = \frac{-1+-1}{2}$
x1=0
x2=-1