Question

if the mid point of line joining A(5,-1) and B(K,2)is(x,y)and2x+2y+1=0find the value of k

Answer 1

2(5, -1)+2(k, 2)+1= (10,-2)+(2k, 4)
=(8+2k+4)=(12+2k)
= k=(12+2)
= k=14