The value of QS will be equal to 117 units
QS and RT are the two diagonals of the rectangle QRST.
That means that they are the same length due to the properties of rectangles.
So we set them equal to each other and solve for x.
4x-15 = 3x+18
4x-3x = 18+15
x = 33
Now that we have that x = 33, we can substitute back into the equation for QS and get:
(4*33)-15 = 117 units
We can check that x = 5 is a true solution by substituting it into the equation for RT as well:
(3*33)+18 = 117 units
Since both equations come to the same value when x = 33, then x = 33 is a solution for this set of equations and the length of the diagonal QS is equal to 117 units
The complete question may be like:
In a rectangle QRST, QS=7x+4 and RT=3x+24. What is the length of QS?