+502 http://papers.xtremepapers.com/CIE/Cambridge%20IGCSE/Mathematics%20(0580)/0580_s11_qp_22.pdf
Help me in question number 18
+118703 Let see
A(7,0) B(5,3)
Midpoint of AB = (7+52,0+32)=(6,1.5)
equation of CB
The y intersept is 4 b=4
Draw in the right angled triangle between the points B and C and you can see the gradient m
i.e.
m=riserun=−15
so the equation of BC is
y=−15x+4y=−x5+4
+118703 The midpint is just (the average of the 2 x values, the average of the 2 y values)
To get the average of 2 numbers you add them together and divide by 2
So the average of 12 and 5 for instance is (12+5)/2 = 17/2 = 8.5
If you want the more formal look,
The mid point of
(x1,y1)and(x2,y2)is(x1+x22,y1+y22)
The y intercept is where the line crosses the y axis and you can see that it crosses at 4
SO the y intercept, which is always given the letter b =4
