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.
Answer:
t ≤ 
Step-by-step explanation:
t−3−3t≥3t+6−3t
t−3≥6
-
−3+3≥6+3
t≥9
(
t) ≥
(9)
t ≤ 
Answer: x = -3
Step-by-step explanation:
i simply divided by -7, in order to get x by itself.
-7/-7x = 21/-7
that cancels out the -7 on the left side, and leaves us with -3 on the right side!
x = -3
Answer:
y = 4
Step-by-step explanation:
8(y+4)-2(y-1)=70-3y
8y+32-2y+2=70-3y
Grouping of like terms
8y-2y+3y=70-32-2
9y=36
Divide both sides by 9
9y/9 = 36/9
9 cancels itself and 9.
y=36/9
y=4
Therefore, y = 4.
Hope it helps.
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