A highway is shown as a straight line on a coordinate grid. One end of the highway is located at (5, 9) and the other end is located at (3, -7). Sam performed the steps shown to find the coordinates of the midpoint of the highway.

Step 1. x1 = 5, y1 = 3, x2 = 9, y2 = -7
Step 2. x is equal to all of x1 plus x2 by 2 and y is equal to all of y1 plus y2 by 2.
Step 3. x is equal to all of 5 plus 9 by 2 and y is equal to all of 3 minus 7 by 2.
Step 4. x is equal to 14 by 2, y is equal to -4 by 2.
Step 5. x = 7, y = -2

In which step did Sam first make an error?

Step 4, because he did

Question

A highway is shown as a straight line on a coordinate grid. One end of the highway is located at (5, 9) and the other end is located at (3, -7). Sam performed the steps shown to find the coordinates of the midpoint of the highway.

Step 1.  x1 = 5, y1 = 3, x2 = 9, y2 = -7
Step 2. x is equal to all of x1 plus x2 by 2 and y is equal to all of y1 plus y2 by 2.
Step 3. x is equal to all of 5 plus 9 by 2 and y is equal to all of 3 minus 7 by 2.
Step 4. x is equal to 14 by 2, y is equal to -4 by 2. 
Step 5. x = 7, y = -2 

In which step did Sam first make an error?

Step 4, because he did

anonymous · Answer

In which step did Sam first make an error?

Step 4, because he did not use a negative sign for the x value.

Step 1, because he used the incorrect values for values for x2 and y1.

Step 2, because he used the incorrect formula to find the midpoint.

Step 3, because he changed the positive sign to a negative sign to find y.

anonymous · Answer

can some help me please