panda557 panda557

03-06-2016
Mathematics

contestada

What is x^2+x-20=0.
please help

Respuesta :

meerkat18 meerkat18

03-06-2016

x² + x - 20 = 0

x² = x * x
x = the sum of the factors of -20
-20 ⇒ 1 x 20
2 x 10
- 4 x 5 ⇒ only these factors can arrive to a sum of 1

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

x - 4 = 0
x = 4

x + 5 = 0
x = -5

Answer Link

Otras preguntas

integers from 1 to 50

read the article below and answer the following question. which statement below gives us a clue as to the historical context of this particular football champio

Mutation is an important mechanism for evolutionary change. Which type of mutations contribute to evolution? Germinal mutations Somatic mutations Both somatic

Which is the best definition of wind? A. the vertical movement of air B. the horizontal movement of air C. the westerly movement of air above the Earth's sur

Which best describes the change in the East African slave trade after 1500? The slave trade was outlawed in East Africa after 1500. The slave trad

compare square root of 6 and square root of 8

what would the phrase "twice the sum of a number and three" look like as a variable expression? 2(2n−3) 2(n 3) 2 (2n 3) 2n 3

write -12 as an fraction

The presence of paired chromosomes makes a ____ cell (diploid, germ, haploid, gamete), while a single member of a pair of chromosomes makes a ___ cell (haploid,

__________ papel es blanco