Step-by-step explanation:
h = -490t² + 1470t
When h = 980:
980 = -490t² + 1470t
Simplifying:
0 = -490t² + 1470t - 980
0 = t² - 3t + 2
Factoring:
0 = (t - 1) (t - 2)
t = 1, 2
There are two solutions because the rocket first reaches the height of 980 cm as it's going up at 1 second, then it reaches that height again as it's coming down at 2 seconds.
543 rounded to the nearest hundred is 500
4- 2+3=5
5- 4+1=6
6- 6+5=11
Answer:
sorry I don't remember bye I will try to remember
You could use them to add 154 to 237 (using a flat, 5 longs and 4 units to make 154 and 2 flats, 3 longs and 7 units to get 237). Then once you've put them together, you'll count 391 (you'll have to move the decimal back to 3.91 to get <span>the answer).</span>