Answer:
a. 15 meters.
b. 20 meters.
Step-by-step explanation:
a. The height of the ball at 3 seconds. 20 * 3 - 5 * (3)^2 = 60 - 5 * 9 = 60 - 45 = 15.
The ball will be 15 meters high.
b. The maximum height reached by the ball.
To get that, we need to find the vertex of the parabola. We do so by doing -b/2a to find the x-coordinate of the vertex.
In this case, a = -5 and b = 20.
-20 / 2(-5) = -20 / -10 = 20 / 10 = 2.
Then, we find the y-coordinate by putting 2 where it says "t".
h(2) = 20(2) - 5(2)^2 = (40) - 5(4) = 40 - 20 = 20 meters.
Hope this helps!
Answer:
3x - y = -7
Step-by-step explanation:
y = mx + b
m = deltay/deltax
m = (10 - 1)/[( 1 - (-2)]
m = 9/3 = 3
y = 3x + b
From (-2 | 1) we see that when x = -2, y = 1
Placing into the equation, in order to find b (y-intercept)
y = 3x + b
1 = 3(-2) + b
b = 7
y = 3x + 7 or 3x - y = -7
Answer:

Step-by-step explanation:
This book has 500 pages in total.
We should split up the place values.
1 - 9
One only appears once.
1
10 - 19
One appears 11 times.
1 + 11
20 - 99
One only appears 8 times.
1 + 11 + 8
Add:
1 + 11 + 8
=> 20
Since the same is for 200-299, and so on. Let us add twenty four times.
20 * 4
=> 80
Looking back to 100-199, there are 120 ones.
Add:
120 + 80
=> 200
Answer:
i need more info. that part dont help. if you took pic of the sentence they gv you that would be easier to work with.
Step-by-step explanation: