x3-3x2-x2-3x-then-cancels-x2-terms-to-get-x3-3x-which-error-did-the-student-make

Question

A student writes $$(x^{2} + x)(x + 3) $$and expands it as $$x^{3}$$ + $$3x^{2}$$ + $$x^{2} + 3x$$, then cancels $$x^{2}$$ terms to get $$x^{3} + 3x. $$Which error did the student make?

Accepted Answer

The student incorrectly canceled like terms instead of combining them

Answer

The student multiplied x by 3 incorrectly

Answer

The student added the exponents instead of multiplying $$x^{2} by x$$

Answer

The student failed to use the distributive property properly

A student writes (x2 + x)(x + 3) and expands it as x3 + 3x2 + x2 + 3x, then cancels x2 terms to get x3 + 3x. Which error did the student make?

A student writes (x² + x)(x + 3) and expands it as x³ + 3x² + x² + 3x, then cancels x² terms to get x³ + 3x. Which error did the student make?