FIRST PERSON TO ANSWER CORRECTLY WITH WORK SHOWEN GETS THE PTZ?

Joan can paint a house in 6 days. Tom can paint it in 9 days. If Joan works alone for 2 days and then is joined by Tom, how long would it take to paint the house? (HINT : The equation is 1/6t(t1) + (1/6(t2) + 1/9(t2) ) = 1 where (t1) is the time Joan works alone, and (t2) is the time they work together.)