Answer:
5 jumps
Step-by-step explanation:
Personally I would write it out, although there surely is a formula for it.
3 fall to 2 - 5 fall to 4 - 7 fall to 6 - 10 fall to 9 - 12.
This makes 5 jumps, since once he is out he won't fall back in.
Answer:
-15
Step-by-step explanation:
x=5
X² + y² = 225
x - 7y = -75
x = 7y - 75
x² + y² = 225
(7y-75)² + y² = 225
(7y - 75)(7y - 75) + y² = 225
49y² - 525y - 525y + 5625 + y² = 225
50y² - 1050y + 5400 = 0
50(y² - 21y + 108) = 0
y² - 21y + 108 ⇒ (y - 12)(y - 9)
x = 7(12) - 75
x = 84 - 75
x = 9 ⇒ (9,12)
x = 7(9) - 75
x = 63 - 75
x = -12 ⇒ (-12,9)
Answer: they left home at 8:38
Work:
8:45 + 20 mins = 9:05 (time they arrived)
9:05 - 27 mins = 8:38 (time they left)
