Answer:
Step-by-step explanation:
Let the speed of the car is x, then the speed of motorcycle is x + 20
The distance = 120 km
<u>Time:</u>
- 120/x = 120/(x + 20) + 1
- 120(x + 20) = 120x + x(x +20)
- 120x + 2400 = 120x + x² + 20x
- x² + 20x = 2400
- x² + 2*10x + 10² = 2500
- (x + 10)² = 50²
- x + 10 = 50
- x = 40
Speed of the car is 40 km/h
Speed of the motorcycle is 60 km/h
|x| < 7
means x < 7 and x > -7
answer is -7 < x < 7
Answer:
Incorrect.
Step-by-step explanation:
1 toss could not change the frequency by such a large margin 0.47 ---> 0.55.
The number of heads obtained in 30 tosses = 30 * 0.47 = 14.
So if the next toss came up heads the relative frequency of heads would be
15/31 = 0.48.
Answer:
y=2x+13
Step-by-step explanation:
find gradient which is -2
-7-3/0--5=-10/5 =-2
y-3 =-2. (cross multiply)
x--5
y-3=2x+10
y=2x+13
Answer:
$12.75
Step-by-step explanation:
Skubic Family-
22.75 = 5.25 + 7x
17.5 = 7x
2.5 = x
Therefore the cost for each person is equal to $2.5
Shaw Family-
2.5(3) + 5.25
7.5 + 5.25 = $12.75