Question 27651
If 2 straight lines are perpendicular, having gradients m and n, then we know that m*n = -1.


So, the equation has gradient (-1/2), so our line must have gradient 2.


So, our equation is y=2x+c. Now find c by putting in a set of (x.y) values --> 6,5).


final answer is y = 2x - 7.


jon.