Answer:
42 units
Step-by-step explanation:
If R is the midpoint of QS, then by definition, QR = RS. Since QR = 8x - 51 and RS = 3x - 6, set these equal to solve for x:
QR = RS
8x - 51 = 3x - 6
5x = 45
x = 9
Now that we know x = 9, we can plug this back into one of the expressions for QR or RS to find its length:
QR = 8x - 51 = 8 * 9 - 51 = 72 - 51 = 21
Since half of QS is 21, then the whole of QS is twice that:
2 * 21 = 42
The answer is thus 42 units.
<em>~ an aesthetics lover</em>
