How do you solve #x^2=21x#?

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Answer 1 · 2015-05-20T15:54:22

#x^2=21x#

rewriting the equation:
#x^2 - 21x = 0#

taking out the common term #x#
#x( x - 21) = 0#

equating with #0#
# x = 0 or x-21 =0#

#color(green)(x = 0 ,21# are the two solutions

Answer 2 · 2015-05-20T15:54:59

#x^2 = 21x#

#x^2 - 21x = 0#

#x*(x-21) = 0#

#=> x_1 = 0, x_2=21#.