Question 39 Answer and Explanation _ACT July 2020 Form C01 Math Section

Question 39 Answer and Explanation _ACT July 2020 Form C01 Math Section

ACT Test Explanations Profile Exam History

Logout

39. Which of the following expressions is equal to $\left({a+\sqrt{b}}\right)\left({a-2\sqrt{b}}\right)$ for all positive real numbers a and b?

A. ${a}^{2}-3a\sqrt{b}$

B. ${a}^{2}-a\sqrt{b}-2b$

C. ${a}^{2}-a\sqrt{b}-2\sqrt{2b}$

D. ${a}^{2}-3a\sqrt{b}-2b$

E. ${a}^{2}+3a\sqrt{b}-2b$

Answer and Explanation

Your Answer is

Correct Answer is B

Explanation

Multiplication of polynomials