Question

Find x, if distance between points L(x, 7) and M(1, 15) is 10. A 7 B) 7 or-5 C) -5 D) 10​

Answer 1

Answer:

$10 = \sqrt{ ( {15 - 7)}^{2} + {(1 - x)}^{2} } \\ = > 10 = \sqrt{ 8^{2} + 1 + 2x + {x}^{2} } \\ = > 10 = \sqrt{64 + 1 + 2x + {x}^{2} } \\ = > 10 = \sqrt{8 \times 8 + 1 + 2x + x \times x} \\ = > 10 = 8 + x + 1 \sqrt{2x} \\ = > 2 = x\sqrt{2x} \\ = > x = \frac{ \sqrt{2 } \times \sqrt{2} }{ \sqrt{2} \times \sqrt{x} } \\ \\ = > x = \sqrt{ \frac{2}{x} } \\ \\ = > {x}^{2} = \frac{2}{x} \\ \\ = > {x}^{3} = 2 \\ \\ = > x = \sqrt[3]{2}$