Answer:
x is equal to 6√3
Step-by-step explanation:
[tex] - \frac{2}{3} \sqrt{5} . \: { \boxed{x}}. \: \sqrt{7} = - 4 \sqrt{105} \\ \\ - \frac{2}{3} \sqrt{5} .{ \boxed{x}}. \sqrt{7} = - 4( \sqrt{3} \times \sqrt{5} \times \sqrt{7} ) \\ \\ - \frac{2}{3} x = - 4 \sqrt{3} \\ \\ x = \frac{12 \sqrt{3} }{2} \\ \\ x = 6 \sqrt{3} [/tex]
