3) the point A has coordinates (-3,2) and the point B has coordinates (7,k)
the line AB has equation 3x+5=1
a) i) show that k= -4
ii) hence find the coordinates of the midpoint AB
b) find the gradient of AB
c) a line which passes through the point A is perpendicular to the AB. Find an equation of this line, giving your answer in the form px + qy + r = 0. Where p,q and r are intergers
d) the line AB, with equation 3x+5y=1 , intersects the line 5x + 8y = 4 at the point C. Find the coordinates of C