MID-POINT 1

Find a if the midpoint of a line from (a, 6) to (4, 10) is (7, 7)

Solution

x1=a, x2=4, y1=6, y2=10.

(7, 7)= (x1 + x2, y1 + y2)

                 2             2

(7, 7)= (a + 4,  6 + 10)

                2          2

(7, 7)= (a + 4, 16)

                2      2

Equating values of x;

7= a + 4

        2      

2 x 7= (a + 4)  x 2 ¹

              2 ₁     

14 = a + 4

14-4 = a

a = 10.

Hence a=10

TRY THIS……………………..

Find a if the midpoint of a line from (a, 12) to (7, 10) is (3, 11)