Which of the equations are true identities?A. (a+b)(2a+1)=a(2a+2b+1)B. (n+2)2−n2=4(n+1)Choose 1 answer:(A) Only A(B) Only B(C) Both A and B(D) Neither A nor B
Q. Which of the equations are true identities?A. (a+b)(2a+1)=a(2a+2b+1)B. (n+2)2−n2=4(n+1)Choose 1 answer:(A) Only A(B) Only B(C) Both A and B(D) Neither A nor B
Expand Expression: Expand (a+b)(2a+1) using the distributive property.(a+b)(2a+1)=a(2a)+a(1)+b(2a)+b(1)=2a2+a+2ab+b
Compare Expanded Forms: Compare the expanded form with the right side of equation A.2a2+a+2ab+b?= a(2a+2b+1)= 2a2+2ab+a
Identify Missing Term: Notice that the term ' extit{b}' is missing on the right side of equation extit{A}. Therefore, equation extit{A} is not a true identity.
Apply Binomial Theorem: Expand (n+2)2 using the binomial theorem.(n+2)2=n2+2⋅2n+22=n2+4n+4
Subtract and Simplify: Subtract n2 from both sides of equation B.(n+2)2−n2=4n+4
Compare Results: Compare the result with the right side of equation B.4n+4=4(n+1)=4n+4
Verify Identity: Since both sides of equation B are equal after simplification, equation B is a true identity.