C, because that’s the way to prove the law of sines.
Answer:
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Step-by-step explanation:









4(x+3)=7
The mistake is with his final answer, he wrote down 4x=1.
When you do 4(x)4(3), the answer is completely different from what Andre said. He did wrong calculations.
4x3=12
7-12= -5
Which means it should be 4x=-5 as the final answer.