Final answer:
To find ST, set up an equation by setting RS equal to ST. Solve for x and substitute it back into the equation to find ST.
Step-by-step explanation:
To find ST, we need to first set up an equation using the information given. We know that S is the midpoint of RT, so RS is equal to ST. We also know that RS is equal to 2x+4 and RT is equal to 8x. Setting these two equal to each other, we have: 2x+4 = 8x. Solving for x, we subtract 2x from both sides and then divide by 6 to get x = 2/3. Now that we have the value of x, we can substitute it back into the equation to find ST. So, ST = 2(2/3) + 4 = 8/3 + 12/3 = 20/3 = 6.67 units.