Answer:
QS = 42
Step-by-step explanation:
If R is the midpoint, the QR = RS
QR = RS
8x-51 = 3x-6
Subtract 3x from each side
8x-3x-51 = 3x-3x-6
5x -51 =-6
Add 51 to each side
5x -51+51 = -6+51
5x = 45
Divide by 5
5x/5 = 45/5
x = 9
RS = 3x-6
RS = 3*9-6
= 27-6
= 21
QS = QR + RS
= RS +RS
= 2RS
= 2 *21
= 42
