Example: Add (2x²-3) and (7x³-4x+1).

Problem

Simplify.
left parenthesis, minus, b, start superscript, 2, end superscript, plus, 4, b, plus, 5, right parenthesis, plus, left parenthesis, 4, b, start superscript, 2, end superscript, minus, 8, b, minus, 4, right parenthesis