Question

dentifying an Error

Jerry solved this equation: 3 ( x  −  14 )  =  136

1. 3x  −  34  =  136

2. 3x  −  34  +  34  =  136  +  34

3. 3x  =  2612  +  912

4. 3x  =  3512

5. ( 31  ) 31 x  =  3512  ( 31)

6. x  =  10512

In which step did Jerry make an error?

In step 2, he should have subtracted  from both sides.

In step 3, he should have found an LCD of 10.

In step 4, he should have subtracted 9 from 26.

In step 5, he should have multiplied both sides by .

Answer 1

Jerry made the error in step 1.

When distributing 3 through (x − 14) you get 3x − 42, not 3x − 34. The correct solution is:

3(x − 14) = 136
3x − 42 = 136
3x = 136 + 42 = 178
x = 178/3 = 59 1/3.