Answer:
H. 6x^2 + 7x + 49
Step-by-step explanation:
= 3x^2 + 14 - 7x + 6 + 29 + 3x^2 + 5x + 9x
Combine like terms
= 6x^2 + 7x + 49
Answer:
- train: 40 kph
- plane: 140 kph
Step-by-step explanation:
Let t represent the speed of the train in km/h. Then 4t-20 is the speed of the plane. Travel times are the same, so we can use the formula ...
time = distance/speed
and equate the travel times.
110/t = 385/(4t-20)
Cross multiplying gives ...
110(4t -20) = 385t
440t -2200 = 385t . . . . . eliminate parentheses
55t -2200 = 0 . . . . . . . . . subtract 385t
t -40 = 0 . . . . . . . . . divide by 55
t = 40 . . . . . . . . . . . add 40; train's speed is 40 kph
4t -20 = 140 . . . . . . find plane's speed; 140 kph
The train's speed is 40 km/h; the plane's speed is 140 km/h.
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<em>Check</em>
Train's travel time = 110 km/(40 km/h) = 2.75 h.
Plane's travel time = 385 km/(140 km/h) = 2.75 h.
200,000 and 97
brainliest pls? lol
Answer:
x = -4.59, -7.41.
Step-by-step explanation:
x^2 + 12x + 34 = 0
(x + 6)^2 - 36 +34 = 0
(x + 6)^2 = 36 - 34 = 2
x + 6 = +/-√2
x = +/-√2 - 6
x = -4.59, -7.41
