Answer:
42,008
Step-by-step explanation:
Answer:
a.b=[-1]
Step-by-step explanation:
This is a dot product of a and b
a.b =[6,-2,3].[2,5, -1] = [12-10-3] =[-1]
Answer:
- boat: 6 mph
- current: 2 mph
Step-by-step explanation:
The relationship between time, speed, and distance is ...
speed = distance/time
For boat speed b and current speed c, the speed downstream is ...
b +c = (16 mi)/(2 h) = 8 mi/h
The speed upstream is ...
b -c = (16 mi)/(4 h) = 4 mi/h
Adding the two equations eliminates the c term:
2b = 12 mi/h
b = 6 mi/h . . . . . divide by 2
Solving the second equation for c, we get ...
c = b -4 mi/h = 6 mi/h -4 mi/h = 2 mi/h
The speed of the boat in still water is 6 mi/h; the current is 2 mi/h.
Answer: Add the equations to eliminate k
Step-by-step explanation:
Adding the equations, you get 2b=18, which you can solve for b. Afterward, you can substitute this value of b back into either equation to solve for k.
Y = 2/7x - 4
y + 4 = 2/7x
4 = 2/7x - y (multiply everything by seven to get rid of the fraction)
28 = 2x - 7y
2x - 7y = 28
