Question

What is the mistake of +7+7 (9×=0(9) x=0

Answer 1

`\begin{gathered} 9x-7=-7 \\ \text{Step 1: Add 7 to both sides:} \\ 9x-7+7=-7+7 \\ 9x=0 \\ \text{step 2: Divide both sides by 9} \\ (9x)/(9)=(0)/(9) \\ x=0 \\ \end{gathered}`

The mistake is the step 2. You need to divide both sides by 9, not multiply both sides by 9