Question

An equation and the steps to solve it are shown below:

2x - one over four of (12x + 4) = 3

Step 1: 2x + 3x + 1 = 3
Step 2: 5x + 1 = 3
Step 3: 5x + 1 - 1 = 3 - 1
Step 4: 5x = 2

In which step was the error made and why?

Step 1, because incorrect signs have been used

Step 2, because the terms have been added incorrectly

Step 3, because a number has been subtracted from both sides of the equation

No error was made

Answer 1

What do you think?

Answer 2

To be honest im not sure:(

Answer 3

start from step three and work backwards. try ruling out one at a time. is it legal to subtract the same number from both sides?

Answer 4

no

Answer 5

the rule of thumb is what you do to one side you do to the other. step three is fine so move on to step two. were the terms in step one added correctly to create step two?

Answer 6

No i dont think so.

Answer 7

add like terms
2x+3x=5x

Answer 8

step two looks good

Answer 9

Ok so which ones the right answer ?

Answer 10

if i rule out step two and step three only one remains

Answer 11

Actually two remains. step one and no error made.

Answer 12

good point however the directions do say minus and i do not see anything in step one that uses a negative sign

Answer 13

so the first one

Answer 14

absolutely

Answer 15

Thanks(:

Answer 16

no worries