Write the equation of the line through the points (4,5) and (12,9)

 y=1/2+1

Step-by-step explanation:

1) Y2-Y1 over X2-X1

9-5=4

12-4=8

4/8 simplify the answer= 1/2

m=1/2

2) subtitute the simplification to one of the points.

y=mx+b

5=1(4)+b

5=4=b

1=b

y=1/2+1

hello from mrbilldoesmath!

answer:

a(n) - a(n-1) -3

discussion:

this ones a bit interesting. given a(n) = 5 - 3n consider this:

a(n-1) = 5 - 3(n-1)

          = (5 - 3n) + 3             => but a(n) = 5 - 3n, the first term

          = a(n)   + 3                 => subtract 3 from both sides

a(n-1) -3 = a(n)  

or

a(n) - a(n-1) -3

you,

mrb