The real numbers aaa and bbb satisfy a+b=6,ab=7.a+b=6,\qquad ab=7.a+b=6,ab=7. What is the value of ab+ba ?\frac ab+\frac ba\,?ba+ab? A67\dfrac6776B87\dfrac8778C227\dfrac{22}7722D297\dfrac{29}7729E367\dfrac{36}7736