Answers Common Core Algebra I 2014 - MA3109 B-CR Solving Quadratic Equations: Completing the Square — Unit testQuestion 10

10

QuizMultiple Choice

Solving Quadratic Equations: Completing the Square — Unit test

Question 10 • Common Core Algebra I 2014 - MA3109 B-CR

Holly finds that (11m – 13n + 6mn) – (10m – 7n + 3mn) = m – 20n + 9mn. What error did Holly make?

Answer

A

She only used the additive inverse of 10m when combining like terms.

B

She added the polynomials instead of subtracting.

C

She only used the additive inverses of –7n and 3mn when combining like terms.

D

She did not combine all like terms.

Explanation

Distribute the subtraction sign to every term in the second polynomial: (11m − 13n + 6mn) − 10m + 7n − 3mn. Holly’s result, m − 20n + 9mn, shows she changed 10m to −10m but left −7n and 3mn unchanged, adding them instead. So she only used the additive inverse of 10m, which is choice A.

AI-written and checked against the verified answer.

More from this Course

15 verified answers

Unit Test

15 verified answers

Unit Test

23 verified answers

Solving Quadratic Equations: Completing the Square