How do you solve #|x+ 30|= 4x#?

1 Answer
filip
Apr 11, 2018

x = 10

Explanation:

  1. we have to find, when the absolute value (ABS) is more than zero and when less
    zero point for this ABS is x=-30
  2. then we will solve this problem for 2 intervals, one interval when ABS is possitive and one when ABS is negative

first interval:
(in this interval ABS is negative therefore we write -(x+30) instead of ABS)
#x in (-oo;-30): -(x+30)=4x#
#-30=5x#
#x=-6#
#but -6!in(-oo;-30) => x=-6 "is not solution"#

second interval:
(in this interval ABS is possitive therefore we write (x+30) instead of ABS)
#x in (-30;oo): (x+30)=4x#
#30=3x#
#x=10#
#10in(-30;oo) => x=10 "is solution"#

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