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Help with Pure Maths please?

A line passes through points (p, 3), (p + 2, 5) and (1, 2) where p > 0. Find the value of k.

what do I do oh what do I do? :cry:

(edited 7 years ago)

Reply 1

NotNotBatman

Original post by honour

A line passes through points (p, 3), (p + 2, 5) and (1, 2) where p > 0. Find the value of k.

what do I do oh what do I do? :'(

I'll assume you mean the value of p.

Find the gradient in terms of p, you can do this using (p,3),(1,2) and (p+2,5), (1,2) and set the gradients equal in terms of p to solve.

Reply 2

Gregorius

Original post by honour

A line passes through points (p, 3), (p + 2, 5) and (1, 2) where p > 0. Find the value of k.

what do I do oh what do I do? :'(

Look at the coordinates of the first two points: there's enough information to work out the gradient of the line from that information - you go up 2 after moving along 2. Now choose p so that the line goes through the final point given.

Reply 3

ℓove

Use this equation: (y2-y1) / (x2-x1) to find the gradient between the first two coordinates: (2-3) / (1-p)
Or you can try (3-5) / p-(p+2), which is -2/-2, giving you a gradient of 1.

So you know that 1 = (2-3) / (1-p)
You can solve p by multiplying each side by (1-p), so 1-p = -1
Add 1 and -p to each side and you'll get 2 = p