The correct answer is B. -12
Answer:
x = -10
Step-by-step explanation:
We just have to translate the problem correctly
>8 times a number is the same
this tells me that
>as 30 less than 5 times the number.
Now set them equal to eachother
Now isolate the variable x
Use distributive property:
(a + b)(c + d) = ac + ad + bc + bd
(y + 1)(y² + 2y + 3) = (y)(y²) + (y)(2y) + (y)(3) + (1)(y²) + (1)(2y) + (1)(3)
= y³ + 2y² + 3y + y² + 2y + 3 = y³ + (2y² + y²) + (3y + 2y) + 3
= y³ + 3y² + 5y + 3
Step-by-step explanation:
Distance = rate × time
If b is the speed of the boat in still water, and c is the speed of the current, then:
60 = (b + c) × 4
35 = (b − c) × 3.5
Simplifying:
15 = b + c
10 = b − c
Add the equations together:
25 = 2b
b = 12.5
Plug into either equation to find c:
c = 2.5
The speed of the boat is 12.5 km/h, and the speed of the current is 2.5 km/h.
Answer: option B is the correct answer.
Step-by-step explanation:
Susan drove at an average speed of 30 miles per hour for the first 30 miles of a trip.
Time = distance/speed
This means that time spent by Susan in travelling the first 30 miles would be
Time = 30/30 = 1 hour
He travelled at an average speed of 60 miles per hour for the remaining 30 miles of the trip.
Time = 30/60 = 0.5 hours
Total distance travelled is 30 + 30 = 60 miles.
Total time spent = 1 + 0.5 = 1.5 hours
Speed = distance/time
Average speed = 60/1.5 = 40 miles per hour.
