Estimate the product choose a method 63 * 18

Phillip had some bricks. he stacked them in 6 equal piles. which expression shows the number of bricks phillip put in each pile? let the variable m stand for the unknown number of bricks. m + 6 m÷6    m−6    6m

Can someone me with this problem . show your work .

For what value of (y) is 3^3/3^y =1/9