Question

Alberto uses the steps below to solve the equation One-half x minus 3 equals 7. Step 1: One-half x minus 3 plus 3 equals 7 plus 3 Step 2: One-half x plus 0 equals 10 Step 3: One-half x equals 0 Step 4: 2 (one-half) x equals 2 (10) Step 5: 1 x equals 20 Step 6: x equals 20 Which justifies Step 6 of his work?

Answer 1

Identity property of multiplication

Explanation:

From step 5:

`1x = 20`

Here, to solve for x so that the variable x stands alone, Alberto uses the identity property of multiplication, which justifies what he has in step 6.

Step 6:

`x = 20`

According to the identity property of multiplication, any value you multiply by 1 gives you that same value.

Therefore, 1x = 1 × x = x.

The variable x multiplied by 1 will give you x.