If a = 2b + 1, then, in terms of b, what is the value of 4a - 5?

To solve this, plug 2b+1 in for a.:

4 (2b+1) - 5. Solve for b.

First use the distributive property:

8b+4-5=?

Combine like terms:

8b-1=?

Solve for b.

add 1 to both sides.

8b=1

Divide both sides by 8.

b=1/8