Final answer:
To find the length of the line segment QS, you add the lengths of segments QR and RS together. Without the value of x, the expression for QS is simplified to 2x + 7.
Step-by-step explanation:
If QR=2x-5 and RS=12, to find QS, we need to add the lengths of QR and RS together. This is because in geometry, the length of a line segment consisting of two connected parts is equal to the sum of the lengths of those two parts. Thus:
QS = QR + RS
QS = (2x - 5) + 12
Now, if we are given the value of x, we could substitute it into the equation and solve for QS. However, without the value of x, we can only simplify the expression for QS, which gives us QS = 2x + 7. To find the exact length of QS, the value of x is necessary.