The answer is [tex] 5 \sqrt{3} [/tex]
[tex] \frac{ {m}^{2} }{15} - 3 = 2[/tex]
[tex] \frac{ {m}^{2} }{15} = 2 + 3[/tex]
[tex] \frac{ {m}^{2} }{15} = 5[/tex]
[tex] {m}^{2} = 5 \times 15[/tex]
[tex] {m}^{2} = 75[/tex]
[tex]m = \sqrt{75} [/tex]
[tex]m = \sqrt{25 \times 3} [/tex]
[tex]m = \sqrt{25} \times \sqrt{3} [/tex]
[tex]m = 5 \sqrt{3} [/tex]
CMIIW