Numbers? Letters? Objects?
<span>70 thousand is written in word form because the word ‘thousand’ is written out. In standard form a number is represented by a decimal and 10 to the power of a number.</span>
Answer: 
<u>Step-by-step explanation:</u>
Insert x = 13 and y = 1:
x² + 2hxy + 12y² = 0
(13)² + 2(13)(1) + 12(1)² = 0
169 + 26h + 12 = 0
26h + 181 = 0
26h = -181
speed with no wind = s
speed with wind = s + 5
speed against wind = s - 5
time = t
speed = distance/time
distance = speed * time
With wind, time = t, speed = s + 5, distance = 50
50 = (s + 5)t
Against wind, time = t, speed = s - 5, distance = 30
30 = (s - 5)t
t = 30/(s - 5)
50 = (s + 5) * 30/(s - 5)
50(s - 5) = (s + 5) * 30
50s - 250 = 30s + 150
20s = 400
s = 20
Answer: 20 mph
