Question

mohon jawaban dan pembahasan lengkapnya kak​

Answer 1

Jawaban:

B

Penjelasan dengan langkah-langkah:

[tex] \frac{x1}{x2} = \frac{1}{4} \\ 4x1 = x2[/tex]

[tex]2 {x}^{2} - kx + 18 = 0[/tex]

[tex]x1.x2 = \frac{c}{a} \\ x1.4x1 = \frac{18}{2} \\ 4 {x1}^{2} = 9 \\ {x1}^{2} = \frac{9}{4} \\ x1 = \sqrt{ \frac{9}{4} } \\ x1 = \frac{3}{2} [/tex]

[tex]4x1 = x2 \\ 4. \frac{3}{2} = x2 \\ 6 = x2[/tex]

[tex]x1 + x2 = \frac{ - b}{a} \\ \frac{3}{2} + 6 = \frac{k}{2} \\ 7 \frac{1}{2} = \frac{k}{2} \\ \frac{15}{2} = \frac{k}{2} \\ k = 15[/tex]