Question

The work of a student to solve the equation 2(5y – 2) = 12 + 6y is shown below: Step 1: 2(5y – 2) = 12 + 6y Step 2: 7y – 4 = 12 + 6y Step 3: y – 4 = 10 Step 4: y = 14 Step 5: y = 7 In which step did the student first make an error and what is the correct step? (1 point) A: Step 2: 7y – 4 = 6 + 3y B: Step 2: 10y – 4 = 12 + 6y C; Step 3: 5y – 2 = 2(10 + 3y) D: Step 3: 2(5y – 2) = 10 + 3y

Answer 1

2(5y - 2) = 12 + 6y
7y - 4 = 12 + 6y ⇒ wrong, it has to be: 10y - 4 = 12 + 6y

so the correct answer is B

Answer 2

Option B

Step 2:
`10y-4=12+6y`

Explanation:

We are given that an equation

`2(5y-2)=12+6y`

We are given steps which are solved by student .We have to find the first error he makes in her/his steps and correct it.

Step1:
`2(5y-2)=12+6y`

Step 2:
`10y-4=12+6y`

But student did in step 2:
`7y-4=12+6y`

So , he makes error in step 2

Step 3:
`10y-6y=12+4`

Step 4:
`4y=16`

Step 5:
`y=(16)/(4)=4`

Hence, option B is true , step 2:
`10y-4=12+6y`