Home » Test Prep » PSAT Test » Which of the following statement(s) is(are) true:
Given a × b = (a + b)/(a – b) and b × a = (b + a)/(b – a), which of the following statement(s) is(are) true:
I. a × b = -(b × a)
II. (a × b)(b × a) = (a × b)2
III. a × b + b × a = 0
A. I only
B. I, II and III
C. I and III
D. I and II
E. II & III
Correct Answer: C
Explanation/Reference:
Explanation:
Notice that -(a – b) = b – a, so statement I & III are true after substituting the expression. Substitute the expression for statement II gives ((a + b)/(a – b))((a + b)/(b – a)) = ((a + b)(b + a))/((-1)(a – b)(a – b))= -1 [(a + b)]2/[(a – b)]2 = -((a + b)/(a – b))2 = -(a × b)2 ≠ (a ×b)2
|
Download Printable PDF. VALID exam to help you PASS.
|
 |
