0.00013x^2 + 0.0063x - 4.7=0

Question

Ans: x= -215.91,167.45

Find x

I used -b± sqr b^2-4ac/2a

I couldn't get that answer.

please help.

Answer 1

In that case, you made a mistake

b^2 = 0.0063^2 = 0.00003969
4ac = 4(.00013)(-4.7) = -0.002444
b^2-4ac = 0.00248369
√(b^2-4ac) = 0.04984
(-.0063+0.04984)/.00026 = 167.45
(-.0063-0.04984)/.00026 = -215.91