a(n)=3+(n-1)(-4)

Solution for a(n)=3+(n-1)(-4) equation:

Simplifying
a(n) = 3 + (n + -1)(-4)

Multiply a * n
an = 3 + (n + -1)(-4)

Reorder the terms:
an = 3 + (-1 + n)(-4)

Reorder the terms for easier multiplication:
an = 3 + -4(-1 + n)
an = 3 + (-1 * -4 + n * -4)
an = 3 + (4 + -4n)

Combine like terms: 3 + 4 = 7
an = 7 + -4n

Solving
an = 7 + -4n

Solving for variable 'a'.

Move all terms containing a to the left, all other terms to the right.

Divide each side by 'n'.
a = 7n-1 + -4

Simplifying
a = 7n-1 + -4

Reorder the terms:
a = -4 + 7n-1