If a ball is thrown directly up at 30 meters per second, its height (in meters) after t seconds is given by h(t) = 30t - 5t^2. What is the maximum height (in meters) attained by the ball?

45m

Step-by-step explanation:

t = -30/(-2×5) = 3

Max height at t = 3

30(3) - 5(3)² = 45m

it is a reproduction.

step-by-step explanation:

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18