Question

Factorise the following by grouping the terms:
4abx² + 49aby² + 14xy(a² + b²)

Answer 1

4abx² + 49aby² + 14xy(a² + b²)
= 4abx² + 49aby² + 14a²xy + 14b²xy
= (4abx² + 14a²xy) + (14b²xy + 49aby²)
= 2ax(2bx + 7ay) + 7by(2bx + 7ay)
= (2bx + 7ay)(2ax + 7by).