Answer:
Step-by-step explanation:
You want to Foil. As shown in the image below....
so you want to multiply a*9a=9a^2
second multiply -b * 6b= -6b^2
Third multiply -b* 9a= -9ab
Fourth a*6b=6ab
Now you want to combine LIKED TERMS
liked terms are 6ab and -9ab add em together an it equals
-3ab
after you COMBINED LIKED TERMS YOU WANT TO PUT IT INTO STANDARD FORM (greatest degree to least degree)
9a^2-6b^2-3ab
THIS IS HOW IT SUPOSED TO LOOK ( LOOK AT PICTURE)