We Distribute, Yet Things Multiply — Chapter Summary

The basic form is a(b +

The basic form is a(b + c) = ab + ac. It means a number outside a bracket multiplies each term inside the bracket. The reverse form is (a + b)c = ac +

If one number in ab

If one number in ab is increased by 1, then a(b + 1) = ab + a. So the product increases by a.

Useful forms include (a + u)(b

Useful forms include (a + u)(b - v) = ab + ub - av - uv, (a - u)(b + v) = ab - ub + av - uv, and (a - u)(b - v) = ab - ub - av + uv.

The distributive property is not limited

The distributive property is not limited to two terms inside a bracket. It also works when there are three or more terms, by multiplying each term sep

(a + b) × (a^2 +

(a + b) × (a^2 + 2ab + b^2) = a^3 + 3a^2b + 3ab^2 + b^3.