A point is written using the form (X,Y), so the first number is the X and the second number is the Y.
Replace x and Y in the given equation with the given point:
y ≤ 3x+1
9 ≤ 3(2) +1
9 ≤ 6 +1
9 ≤ 7
9 is not less than or equal to 7, so the point (2,9) does not satisfy the inequality.
Turn 45% into a decimal. You get 0.45, because you move the decimal two places to the left.
Then multiply 300*0.45
You get 135
135 Shoppers in the supermarket bought milk.
The last one is correct because 60+35+35+35=165
55+55+55=165