So let's start by guesstimating the slopes:
the green line has a slope close to -x, but more negative than that, possibly -2; the pink line has a slope close to +x, but higher towards +2.
Next let's look at the solution: the two lines intersect at the point (1, -1).
**you could just simple plug that x (1) into all the equations, but let's rule out answers anyway. ;)
A) is incorrect because the slopes of -1 and +1 are off from out predicted -2 and +2
B) is incorrect because of a similar reason, the slopes of +3 and +1 don't make any sense
C) Ooh, we do have a +2 and -2 for the slopes, and... violà! plug in 1 for the x's and we get -1 for the y in both equations
D) slopes are closer than in A and B, but plugging in 1 doesn't get us -1
So the correct answer is:
C) y = 2x - 3 and y = −2x + 1
To find how long it will take to fill the tank, you can use the idea that every 30 seconds will get you one gallon closer to being full.
This means to fill 50 gallons, you will need 50 groups of 30 seconds.
50 x 30 = 1500 seconds
1500/60 = 25 minutes.
It will take 25 minutes.
You could also think of it as filling 2 gallons every minute. It would take 25 of these.
Step-by-step explanation:
2+2+2+2+2÷2×2-2-2-2-2=2
