Answer:
Step-by-step explanation:
- speed = distance / time
- time = distance / speed
a)
i)
<u>Time taken at the first part:</u>
ii)
<u>Time taken at the second part:</u>
- (190 - 105) / (x + 12) =
- 85/(x + 12)
b)
<u>If time is 3 hours and 15 minutes = 3 1/4 hours = 13/4 hours, the equation is:</u>
- 105/x + 85/(x + 12) = 13/4
- 4(x + 12)*105 + 4(85x) = 13x(x + 12)
- 13x² - 604x - 5040 = 0
c)
<u>Solve the equation:</u>
- 13x² - 604x - 5040 = 0
- x = [604 ± √((-604)² + 4*13*5040) ]/26 =
- [604 ± √626896]/26 =
- [604 ± 791.77]/26
- x = (604 + 791.77)/26 = 53.68 km/h (taking positive root only)
d)
- 105/x = 105/53.68 h = 1.956 h = 1 h 0.956*60 min = 1 h 57 min (rounded)
- 85/(53.68 + 12) = 85/65.68 = 1.294 h = 1 h 0.294*60 min = 1 h 18 min (rounded)
1200/8 = x/3
150 = x/3
150 * 3 = x
450 = x
450 calories
One is 153!8 two is jehdbhudiexxxiicicfff
third picture shows cube root of 64=4
