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

Divide the following rectangle into four equal sections using a compass and basic constructions

What is a musical piece in which was solo instrument is a accompanied by an orchestra

Suppose u⎯⎯⎯=⟨−1,1⟩u¯=⟨−1,1⟩ and v⎯⎯⎯=⟨0,−2⟩v¯=⟨0,−2⟩ are two vectors that form the sides of a parallelogram. then the lengths of the two diagonals of the paral

help would be much appreciated

Factor the expression: 40x + 15

which sentence is correct? 1, After the operation, Bo said he'd never felt so good. 2, Bo said he never felt so bad 3, Bo said he'd never felt so badly 4, Bo

Problem: You must find the horizontal distance between two towers (points A and B) at the same elevation on opposite sides of a wide canyon running east and wes

Can somebody explain to me how they got 3^4(x) = 3^3(x+2)? Then explain what happened to the 3 in 3^4 and the 3 in 3^3? Please and thank you, I don't understand

Two trains begin in Milford and end in Pinkerton, which is 300 miles away. Train A leaves Milford at 10:00 a.M. And travels at a rate of 90 miles per hour. Trai

In which continent would you find this coordinate 62 n 106 e