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Find two points on the graph that the line crosses through almost perfectly. It looks like (1,10) and (9,1) will do.
Use them to compute the slope:
m = (1 - 10) / (9 - 1)
= -9/8
Then set up the "point-slope form":
y - y0 = m * (x - x0)
You choose some point (x0, y0) that the line crosses through. We already know the line passes through (1,10) pretty well, so let's use that.
x0 = 1
y0 = 10
Now finish plugging into the equation:
y - 10 = -9/8 * (x - 1)
The above equation will work fine for an answer, but let's go a step further and solve for y.
y - 10 = -9/8x + 9/8
y = -9/8x + 9/8 + 10
y = -9/8x + 9/8 + 80/8
y = -9/8x + (9 + 80)/8
y = -9/8x + 89/8
95x=85x+288
You could add 288 to any side, it just shows that they're 288 miles apart.
Let's subtract 85x from both sides.
10x=288
28.8=x
It'll take 28.8 hours for the trains to meet. Let's make sure.
28.8×95
2,736
28.8×85
2,448
2,736-2,448
288
So, they'll meet up after 28.8 miles.
So long as the perimeters are the same, rectangles and squares share the same area. For example, a square that is 2m by 2m across is 4m squared. A rectangle of 4m by 1m across is still 4m squared.
Therefore all we want to do here is see how big we can make our “square” perimeter using the creek. We have three sides to spread 580ft across, therefore if we divide this by 3, we get 193.3ft of fencing per side. If we then square this figure, we will then get the maximum possible area, which comes to 37,377ft squared. (That’s a huge garden).
Answer:
-2497
Step-by-step explanation:
Sn=n/2[2a+(n-1)d]
=22/2[2*-40+(22-1)d]
=11(2*-40+(21*-7)
= -2497
