Answer:
4 sec
Step-by-step explanation:
let y = 0 which is the height when the rocket hits the ground
-3t^2 + 6t + 24 = 0
-3(t^2 - 2t - 8) = 0
-3(t - 4)(t + 2) = 0
t = 4 or t = -2
time cannot be negative, so t = 4 sec
Answer:
A. (-7 -2)
Step-by-step explanation:
You can eliminate y by multiplying the first equation by 7 and subtracting 6 times the second equation:
7(-3x +6y) -6(5x +7y) = 7(9) -6(-49)
-21x +42y -30x -42y = 63 +294 . . . . eliminate parentheses
-51x = 357 . . . . . . . . collect terms
x = -7 . . . . . . . divide by -51. This matches answer choice A.
Answer:
75,361,700
Step-by-step explanation:
find the hundredths place, if the number to the right is higher than or equal to 5 increase the number in the hundredth place by 1, if not keep the number the same (so 6 will turn into 7) and make the numbers after that 0s. Copy down the numbers exactly like they are but with the rounded hundredth place.
