Algebra

Misusing the Distributive Property

Students multiply only the first term inside parentheses, such as writing 3(x+4)=3x+43(x+4)=3x+4.

Quick check

Why students make it

The parentheses can feel like one step, so students multiply the first visible part and then copy the rest. They forget that every term inside the parentheses is being multiplied by the outside factor.

The rule done right

Multiply the outside factor by each term inside the parentheses. In general, a(b+c)=ab+aca(b+c)=ab+ac and a(b−c)=ab−aca(b-c)=ab-ac.

Related resources

distributive-propertyexpressionssimplifying