Get zeroes of following questions? x^3-4x And √5x-5

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Answer 1 · 2018-04-27T06:55:20

#x=0,+-2# for the first equation, and #x=5# for the second.

Part 1. #x^3-4x#

Given: #x^3-4x=0#

Factor.

#=>x(x^2-4)=0#

Use the difference of squares, #a^2-b^2=(a-b)(a+b)#.

#=>x(x-2)(x+2)=0#

#:.x=0,+-2#

Part 2. #sqrt(5x)-5#

Given: #sqrt(5x)-5=0#

#:.sqrt(5x)=5#

Square both sides.

#:.5x=5^2=25#

Divide by #5# to get #x#.

#x=25/5=5#