Which describes the number and type of roots of the equation x3-4x2+50x+7=0?

Question

Problem is x(cubed) - 4x + 50x + 7 = 0

Choices for answer:

1 positive, 2 negatives
2 positives, 1 negative
3 negatives
3 positives

Answer 1

if f(x) change of sign twice

so number of positive roots 0 or 2 based on Descartes rule

from the given case 2 positive so 1 negative

Answer 2

Use the caret ^ (above the 6) to reveal an exponent. x^3 - 4x^2 + 50x + 7 = 0 you should use Descartes' rule of signs and indicators to make sure the "attainable" nature of the roots. evaluate the equation for (x) and for (- x), counting signal alterations. There are (at maximum) 2 sensible roots and a million negative root QED