ABCD is a rhombus on a graph. B(7,10). AC: y=7-4x. Find an equation for DB in the form tx+py+r=0 where t,p&r are integers.

AC and DB must be perpendicular therefore m1m2 = -1. (we can work out the gradient of DB)-4m2 = -1 -----> m2 = 1/4The equation of a line is y-y1=m(x-x1) (sub in x, y and gradient values)y - 7 = 1/4(x-10) (multiply by 4 to get rid of fractions)4y - 28 = x -10 (make = to 0)x - 4y + 18 = 0

AL

Related Maths GCSE answers

All answers ▸

Kelly is trying to work out the two values of w for which 3w - w^3 = 2 Her values are 1 and -1 Are her values correct? You must show your working.


How do I solve simultaneous equations that aren't linear, for example x^2 + 2y = 9, y = x + 3


Find values for x and y from two simultaneous equations: 2x + y = 5 and 3x + y = 7


8 pens in a bag, 3 blue, 5 red. 2 taken out at random, without replacement. Probability they are the same colour?