1. **Stating the problem:** We are given the equation $$3(x-4)^2=27$$ and need to identify mistakes made by Andre and Clare in solving it (Part A), and then find the correct solution(s) to the equation (Part B).
2. **Part A: Analyze Andre's work**
- Andre starts with $$3(x-4)^2=27$$.
- He divides both sides by 3 to get $$(x-4)^2=9$$. This is correct.
- Then he writes $$x^2 - 42 = 9$$, which is incorrect because he incorrectly distributed the square over the subtraction inside the parentheses.
- The correct expansion of $$(x-4)^2$$ is $$x^2 - 8x + 16$$, not $$x^2 - 42$$.
- Andre then solves $$x^2 = 25$$ and finds $$x=5$$ or $$x=-5$$, which are not the correct solutions to the original equation.
3. **Part A: Analyze Clare's work**
- Clare also starts with $$3(x-4)^2=27$$.
- She divides both sides by 3 to get $$(x-4)^2=9$$.
- Then she takes the square root of both sides and writes $$x-4=3$$, ignoring the negative root.
- The correct step should be $$x-4=3$$ or $$x-4=-3$$.
- Clare finds $$x=7$$ but misses $$x=1$$.
4. **Summary of mistakes:**
- Andre incorrectly distributed the exponent over subtraction (which is not allowed).
- Clare ignored the negative root when taking the square root.
5. **Part B: Find the correct solution(s)**
- Starting from $$(x-4)^2=9$$.
- Taking square roots: $$x-4=3$$ or $$x-4=-3$$.
- Solving each:
- $$x=7$$
- $$x=1$$
6. **Final answer:** The solutions to the equation $$3(x-4)^2=27$$ are $$x=1$$ and $$x=7$$.
**Therefore:**
- Mistakes: B) Andre distributed the exponent incorrectly.
- Mistakes: E) Clare left out the negative root.
- Solutions: D) $$x=1$$ or $$x=7$$.
Quadratic Mistakes 5E707E
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