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

mary invested £12000 in a savings account. the account pays 1.5% compound interest per year. work out value of her investment after 2 years

The area of a square is 494949 square meters. how long is each side?

Please answer! Will give branliest! 1. In the reaction 2H2 + _____ O2 ----> 2H2O, what coefficient should be placed in front of O2 to balance the reaction? A

Number Frequency 1,400 3 1,450 7 1,500 7 1,550 5 1,600 4 1,650 2 1,700 1 What is the mode?

What is ten + ten • 2

The minute hand of a clock is 5 inches5 inches long. how far does the tip of the minute hand move in 35 minutes35 minutes?

The short pieces of dna formed on the lagging strand are called

What line, spoken by gertrude, indicates that she was not involved in king hamlet's murder? i'll warrant you,/ fear me not: withdraw, i hear him comin?

Chris plants 40 pumpkin seeds in 5 equal rows. how many seeds does Chris plant in each row?

a hiker descends from a mountain peak. if the hiker descends at a rate of 700 ft every half hour, what is the hikers elevation relative to the peak after 3 hour