I need help solving an=a1+(n-1)d and I'm suppose to solve for d. I need help please :)

Question

anonymous · Answer

transpose a1 to left side.

jdoe0001 · Answer

hmmm, that's just plain simplification, I assume you're not doing sequences evaluations

phi · Answer

The first thing to know is that "an"   and "a1"  are names and do not mean a times n or a times 1

an=a1+(n-1)d

add -a1 to both sides 
an-a1  = a1-a1 + (n-1) d

can you simplify the right side ?

phi · Answer

you should notice that a1 - a1 is 0  so you can simplify to
an  -   a1  = (n-1) d

now divide both sides by (n-1)

can you do that ?

anonymous · Answer

yes.

anonymous · Answer

Give it a try.

anonymous · Answer

got the answer thank u!

phi · Answer

to divide  draw a big line underneath both sides
then write (n-1) under the line  on both sides