jahajahaja jahajahaja

01-09-2016
Mathematics

contestada

What are the zeros of f(x)=x^2+x-20?
A.x=-2 and x=10
B.x=-10 and x=2
C.x=-5 and x=4
D.x=-4 and x=5

Respuesta :

dalendrk dalendrk

02-09-2016

f(x) = x² + x - 20 = x² + 5x - 4x - 20 = x(x + 5) - 4(x + 5) = (x + 5)(x - 4)

f(x) = 0 ⇔ (x + 5)(x - 4) = 0 ⇔ x + 5 = 0 or x - 4 = 0 ⇒ x = -5 or x = 4

Answer: C. x = -5 and x = 4.

Answer Link

Otras preguntas

The two main philosophies in state politics are _____. A)liberalism B)rationalism C)materialism D)conservatism

Which best describes what occurred during the détente era?

joan works for 6 hours each weekday and 8 hours total on the weekends. she earns $6 an hour on weekdays and $9 an hour on weekends. how much money does she earn

If a mitochondrion has a length of 5 µm and a student’s drawing of the mitochondrion is 10 mm, what is the magnification of the drawing? A. ×0.0005 B. ×0.5 C. ×

Which part of speech is not appropriate in formal writing, but often used in daily conversation? A. Conjunction B. Preposition C. Interjection D. Adverb

What does the radiation caution sign mean?

14 line sonnet poem 10 syllables per line about something I hate witch is math.

why does the burning of magnesium ribbon start the reaction between iron oxide and aluminium when making iron?

In the Cayman Islands, in the Caribbean, there is an annual Cinco de Mayo completion. What is the competition? Air guitar Sky-diving Beer drinking Bull Wrestl

Choose the correct Vocabulary word for the blank in the following sentence When someone hurts you , the desire for ______ is strong A. immolation B. retribution