How do you solve the absolute value abs(3x-1) + 10 = 25|3x1|+10=25?

1 Answer
May 13, 2015

Actually there are two conditions to look at:

(1) If 3x-1>=03x10 we have:

(3x-1)+10=25->3x=25+1-10=16->(3x1)+10=253x=25+110=16
x=16//3=5 1/3x=16/3=513

(2) If 3x-1<03x1<0 the absolutes 'turn it around':

-(3x-1)+10=25->-3x=25-1-10=14->(3x1)+10=253x=25110=14
x=14//(-3)=-4 2/3x=14/(3)=423

Validation:
(allways do this, sometimes one of the answers is wrong)
(1) exists if x>=1/3x13 which is consistent with the answer
(2) exists if x<1/3x<13 which is also consistent with the answer

Final answer: x=5 1/3orx=-4 2/3x=513orx=423