The toy rocket hits the ground when h(t) = 0.
So, h(t) = 0 = -9t^2 + 81.
Solving the equation,
-9t^2 = -81
Dividing by -9
t^2 = 9
Taking the square root.
t = 3
The answer is 3 seconds.
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Answer:
x = 4
Step-by-step explanation:
I don't know what you mean by sketch pad but here is the working out
4x + 4 = 20
-4 -4
4x = 16
÷4 ÷4
x = 4
Hope this helps :)
The distance flown by plane is 750 kilometers.
Step-by-step explanation:
Let,
Distance traveled by plane = x
Distance traveled by car = y
Total distance = x+y
According to given statement;
The distance by car was 125 kilometers less than the distance by plane.
y = x - 125 => x=y+125 Eqn 1
The total distance was 500 kilometers less than three times the distance traveled by car.
Total distance = 3y - 500
x+y=3y-500 Eqn 2
Putting value of x from Eqn 1;

Putting y=625 in Eqn 1

The distance flown by plane is 750 kilometers.
Keywords: linear equations, substitution method
Learn more about linear equations at:
#LearnwithBrainly
<span>(x-7)^2 = (x-7)(x-7) = x^2 -7x -7x +49 = x^2-14x+49</span>
answer is 'x^2+14x+49'