A. 1 4/5 + 3 1/8 + 1/2 = 217/40 = 5 17/40 total consumed
B. 6 - 5 17/40 = 23/40 subtract total consumed from original 6
21/10 more than y is 19/5 CORRECT
17/10 + 21/10 = 38/10 simplified to 19/5
34/5 less than y is -51/10 CORRECT
17/10 - 34/5 = 17/10 - 34/5*2/2 = 17/10 - 68/10 = (17-68)/10 = -51/10
15/2 more than y is 29/5 INCORRECT
17/10 + 15/2 = 17/10 + 15/2 * 5/5 = 17/10 + 75/10 = (17+75)/10 = 92/10
18/5 less than y is -53/10 INCORRECT
17/10 - 18/5 = 17/10 - 18/5 * 2/2 = 17/10 - 36/10 = (17-36)/10 = -19/10
The best fit line would show a slope of 1 (if you count the rise/run in that graph, it’s 1/1).
7 L of paint is needed to cover 70m2. For 40m2, you can see that 4 L is needed, which means that for every 1 L, 10m2 can be covered. Multiply 1 L and 10m2 by 7, and you get 7 L is needed for 70m2.