In ΔSTU, \text{m}\angle S = (6x-15)^{\circ}m∠S=(6x−15)

, \text{m}\angle T = (2x-2)^{\circ}m∠T=(2x−2)

, and \text{m}\angle U = (4x-7)^{\circ}m∠U=(4x−7)

. What is the value of x?x?