[x-1]=5x+10 and also [2x+5]=3x+4

Question

[  ] these are absolute value symbols. i dont understand these questions good please help..

Answer 1

Absolute equations must be solved twice. Once assuming the argument (the stuff inside the  |  | is positive, and once assuming it is negative.

 

If x - 1 is positive

 

|x - 1| = 5x + 10

x - 1 = 5x + 10

-1 = 4x + 10

-11 = 4x

-11/4 = x

 

If x - 1 is negative

 

|x - 1| = 5x + 10

-(x - 1) = 5x + 10

-x + 1 = 5x + 10

1 = 6x + 10

-9 = 6x

-9/6 = x

-3/2 = x

 

The second question is done the same way.