Explanation:
Formula for midpoint is ;
m.p = ( x1 + x2/2 , y1 + y2/2)
So x1= 2 and y1 = -9 and the midpoint has already been given so just equate .
( -2 , -1 ) = ( 2 + x2/2 , -9 + y2 /2)
so now equate -2 to 2+x2/2 and -1 to -9 + y2/2
-2 = 2 + x2/ 2. -1 = -9 + y2 / 2
2 + x2 = -4. -9 + y2 = -2
x2 = -4 -2. y2 = -2 + 9
x2 = -6. y2 = 7
Answer:
( -6 , 7 )