Which algebraic identity is most suitable to simplify the numerator in the expression…

MATHEMATICS · Single correct · AP · Calculus AB · Limits and Continuity · Limits and Continuity

Problem

Which algebraic identity is most suitable to simplify the numerator in the expression

\lim_{x\to 5}\dfrac{x^{2}-25}{x-5}

so that the limit can be evaluated? (a)

(a-b)^{2}=a^{2}-2ab+b^{2}

(b)

a^{3}-b^{3}=(a-b)(a^{2}+ab+b^{2})

(c)

a^{2}-b^{2}=(a-b)(a+b)

(d)

(a+b)^{2}=a^{2}+2ab+b^{2}