You have to simplify each equation. You can do that by adding similar values to each other:
(the first equation)
8x²y + 7x² - 5y² + 3x - 2 + 2x²y - x² - 2y² + 3x - 4
To make it easier, arrange the values around so that similar ones are beside each other:
8x²y + 2x²y + 7x² - x² - 5y² - 2y² + 3x + 3x - 2 - 4
then add the similar values together:
8x²y + 2x²y = 10x²y
7x² - x² = 6x²
- 5y² - 2y² = -7y²
3x + 3x = 6x
(- 2)+ (- 4) = -6
and if you put them together:
10x²y + 6x² - 7y² + 6x - 6
This isn't the answer to the equation, because it's different. So repeat the process with all the other equations until you find one that is identical to the simplified version.
The answer is the second one: 8x²y + 7x² - 5y² + 3x - 2 + 2x²y - x² - 2y² - 3x - 4
Step-by-step explanation:
The point-slope form of an equation of a line:

m - slope
(x₁, y₁) - given point

Answer:
640 m
Step-by-step explanation:
We can consider 4 seconds to be 1 time unit. Then 8 more seconds is 2 more time units, for a total of 3 time units.
The distance is proportional to the square of the number of time units. After 1 time unit, the distance is 1² × 80 m. Then after 3 time units, the distance will be 3² × 80 m = 720 m.
In the additional 2 time units (8 seconds), the ball dropped an additional
... (720 -80) m = 640 m
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<em>Alternate solution</em>
You can write the equation for the proportionality and find the constant that goes into it. If we use seconds (not 4-second intervals) as the time unit, then we can say ...
... d = kt²
Filling in the information related to the first 4 seconds, we have ...
... 80 = k(4)²
... 80/16 = k = 5
Then the distance equation becomes ...
... d = 5t²
After 12 seconds (the first 4 plus the next 8), the distance will be ...
... d = 5×12² = 5×144 = 720 . . . meters
That is, the ball dropped an additional 720 -80 = 640 meters in the 12 -4 = 8 seconds after the first data point.
Answer for 1:
I don't know the actual answer, but for Forms, you can press ctrl + U and find the answers in the code
Answer for 2:
x = 28
Step-by-step explanation:
Since the overall angle is 90°, and we already have 33, we subtract 33 from 90
90 - 33 = 57
So we have to fill in the other 57°
2(28) = 56
56 + 1 = 57
So the answer is x = 28