Question

find an equation of the line containing the given pair of points (1,5) & (3,6). y=

Answer 1

y=ax+b
\[a = \Delta Y / \Delta X\] = (6-5)/(3-1) = 1/2=0.5
so y=0.5x + b
since y=5 and x=1:
5 = 0.5 * 1 + b
which gives b=4.5

So y=0.5x+4.5


Check:
6=0.5 * 3 +b
which gives b=4.5 too, so it's correct!