How do you solve the equation #abs(1.2-0.3x)=1.5#?

1 Answer
Apr 3, 2017

Answer:

The equation has 2 solutions: #x_1=-1# and #x_2=9#. See explanation.

Explanation:

First we can see that

#|f(x)|=a iff f(x)=-a vv f(x)=a#

So here we have:

#1.2-0.3x=-1.5 vv 1.2-0.3x=1.5#

Both equalities can be divided by #-0.3#

#-4+x=5 vv -4+x=-5#

Now if we add #4# to both sides of both equations we get the solution:

#x=9 vv x=-1#