Question

Hi. I need help with this questions.
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Answer 1

• None

Explanation:

Given expression

• 9x² - 2(k + 7)x + k

If this is a perfect square then it should be in the form of:

• (3x)² - 2(3x)(√k) + (√k)²

Comparing the two expressions, we see that:

• (k + 7) = 3√k
• (k + 7)² = 9k
• k² + 14k + 49 - 9k = 0
• k² + 5k + 49 = 0
• D = √(5² -4*49) = √-171

Since the discriminant is negative, there is no solution