# Identify the mistake

Algebra Level 4

Tell me at which step I'm going wrong.

1. $$(a+7)=9$$
2. $$(a+7)^{2}=81$$
3. $$a^2 +14a+49=81$$
4. $$a^2 +14a-32=0$$
5. $$a^2+16a-2a-32=0$$
6. $$a(a+16)-2(a+16)=0$$
7. So, $$a=-16$$ and $$a=2$$
8. Putting the value of a in our first equation.
9. $$-16+7=9$$

How is that possible?

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