C-03-Q102mediumsingle_mcqIf p−q=rp - q = rp−q=r, p3−q3−r3=?p^3 - q^3 - r^3 = ?p3−q3−r3=?a3pqr3pqr3pqrb000c−3pqr-3pqr−3pqrdpqrpqrpqrব্যাখ্যাRewrite p−q=rp-q=rp−q=r as p+(−q)+(−r)=0p+(-q)+(-r)=0p+(−q)+(−r)=0. By the identity that x3+y3+z3=3xyzx^3+y^3+z^3=3xyzx3+y3+z3=3xyz when x+y+z=0x+y+z=0x+y+z=0, we get p3+(−q)3+(−r)3=3p(−q)(−r)p^3+(-q)^3+(-r)^3=3p(-q)(-r)p3+(−q)3+(−r), i.e. p3−q3−r3=3pqrp^3-q^3-r^3=3pqrp3−q3−r3=3pqr.