MID POINT 1

Find a and b if the midpoint of a line from (a, 6) to (8, b) is

(30, 7)

Solution

x1=a, x2=8, y1=6, y2=b.

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

                   2             2

(30, 7)= (a + 8,  6 + b)

                  2          2

Equating equal values of x;

30= a + 8

         2      

2 x 30= (a + 8)  x 2 ¹

                2 ₁     

60 = a + 8

60-8 = a

a = 52.

Equating equal values of y;

7 = 6 + b

        2

2 x 7= (6 + b)  x 2 ¹  multiplying by 2 both sides.

                2 ₁     

14 = 6 + b

14 – 6 = b

b = 8

Hence a = 52 and b=8

TRY THIS……………………..

Find m and n if the midpoint of a line from (m, 19) to (13, n) is (9, 11)