The table shows the volume of water in an emptying tank over time. A prediction for the volume at 105 seconds is 497 cm3. Is this a reasonable prediction? No, there is no recognizable pattern in the data from which to make a prediction. Yes, the first differences are all around –70, so a linear function is a good model. Subtracting 70 from 567 results in 497 cm3. No, the first differences are 15, so a linear function is a good model. Subtracting 15 from 567 results in 552 cm3. Yes, the average rate of change is about 8.

answer: 1, 3 and 5 are correct

step-by-step explanation:

(b) 240

step-by-step explanation:

first, we use the pythagorean formula using the given side lengths to find x. then we use x to find the side lengths. then we add the side lengths to find the perimeter.

pythagorean theorem formula:

a^2 + b^2 = c^2

(x - 20)^2 + (x - 40)^2 = x^2

x^2 - 40x + 400 + x^2 - 80x + 1600 = x^2

x^2 -120x + 2000 = 0

(x - 100)(x - 20) = 0

x - 100 = 0 or x - 20 = 0

x = 100 or x = 20

we see that the solution x = 20 must be discarded because it will give a negative side length and a side length of 0. the only valid solution is x = 100.

perimeter = sum of the lengths of the sides

perimeter = x + x - 20 + x - 40

perimeter = 3x - 60

replace x with 100.

perimeter = 3(100) - 60

perimeter = 300 - 60

perimeter = 240

i believe its the last graph