Answer : Option A
Explanation:
we can clearly see that from x+ y=5 we can substitute y = 5-x in y = 9x^2
Option B is clearly incorrect x can not be y -5
Option C is incorrect because y can not be 5 +x
Option D is incorrect because its y = 9x^2 not y^2 =9x^2 so y can not be 3x
if its y^2 = 9x^2 then only implies y = 3x
Answer:
Groups of 12, Groups of 4, Groups of 6, Groups of 18
Step-by-step explanation:
12 x 3 = 36
36 splits evenly into 12, 4, 6, and 18 therefore that is your answer.
Answer:
D. The rate of change must be 20 pounds per minute.
Step-by-step explanation:
At time 0, the amount of sand is 200 lb. Time zero is when it starts, so it is also called the initial time. The initial value is 200 lb, so choices A and B are wrong.
Now look at the difference from time 0 minutes to time 1 minute. The amount of sand went from 200 lb to 220 lb. The amount of sand placed in 1 minute is 20 lb, so the rate of change is 20 lb per minute. That makes choice C wrong and choice D correct.
Answer: D. The rate of change must be 20 pounds per minute.
