Question

An equation and the steps to solve it are shown below: 3x - one over two (8x - 2) = 4 Step 1: 3x - 4x + 1 = 4 Step 2: x + 1 = 4 Step 3: x + 1 - 1 = 4 - 1 Step 4: x = 3 Which step was the error made and why?

Answer 1

The equation is expressed as 3x- 0.5 * (8x-2). In this case, the first step is through distributive property resulting to 3x - 4x + 1 = 4. The incorrect step is the proceeding step (step 2) in which x should have negative sign instead of positive as -4x + 3x is -x. This affects the proceeding steps and thus the answer.

Answer 2

$3x-\dfrac{1}{2}(8x-2)=4\\\\1.\ 3x-4x+1=4-correct\\\\2.\ x+1=4-error,\ correct\ is\ -x+1=4\\\\3^*.-x+1-1=4-1\\\\4^*.-x=3\\\\5^*.\ x=-3$