Let us start by graphing these points on a coordinate plane.(See picture) So, we can see that (-15,21) is in the 2nd quadrant. (4.5,10.6) is in the 1st quadrant. (-3/4,-4 1/9) is in the third quadrant.And finally, (3,-7) is in the 4th quadrant. Then we come to our y axis and the x axis. On the y axis we have (0,12)and on the x axis we have (18,0). Hope this helps!
Answer: Ally would need 6 more quarts of water. Explanation: Since 4 quarts equal 1 gallon, 4*4 = 16 + 2 = 18, Julia would have 18 quarts. Subtract 12 from 18 to get 6 quarts.