Square of a Sum
How to solve the square of a sum problems: formula, examples, and their solutions.
(a + b)2 = (a + b)(a + b).
By using the FOIL method,
(a + b)(a + b) = a2 + 2ab + b2.
So (a + b)2 = a2 + 2ab + b2.
See the brown (+) signs.
The (+) sign in (a + b)2
makes the middle term (+): +2ab.
It's the difference between
this formula and (a - b)2 formula.
Put x, (+), 3 into the formula.
Put 2m, (+), 5n into the formula.