Answer:
2
Step-by-step explanation:
Answer: the rate at which the distance between the boats is increasing is 68 mph
Step-by-step explanation:
The direction of movement of both boats forms a right angle triangle. The distance travelled due south and due east by both boats represents the legs of the triangle. Their distance apart after t hours represents the hypotenuse of the right angle triangle.
Let x represent the length the shorter leg(south) of the right angle triangle.
Let y represent the length the longer leg(east) of the right angle triangle.
Let z represent the hypotenuse.
Applying Pythagoras theorem
Hypotenuse² = opposite side² + adjacent side²
Therefore
z² = x² + y²
To determine the rate at which the distances are changing, we would differentiate with respect to t. It becomes
2zdz/dt = 2xdx/dt + 2ydy/dt- - - -- - -1
One travels south at 32 mi/h and the other travels east at 60 mi/h. It means that
dx/dt = 32
dy/dt = 60
Distance = speed × time
Since t = 0.5 hour, then
x = 32 × 0.5 = 16 miles
y = 60 × 0.5 = 30 miles
z² = 16² + 30² = 256 + 900
z = √1156
z = 34 miles
Substituting these values into equation 1, it becomes
2 × 34 × dz/dt = (2 × 16 × 32) + 2 × 30 × 60
68dz/dt = 1024 + 3600
68dz/dt = 4624
dz/dt = 4624/68
dz/dt = 68 mph
Multiply both sides by 2 to cancel out the 1/2 and you get 2a=bh then divide both sides by h to isolate b and you get (2a)/h=b
Usually, quadratic equations equal 0, and to find the solution you need to make x equal the value that, when added or subtracted to the rest of its bracket, makes 0. This means that your answer is (x + 5)(x - 2) = 0, because 5 - 5 = 0 and 2 - 2 = 0. I hope this helps! Let me know if you would like me to explain further :)
Answer:
B. (-3, -2)
Step-by-step explanation:
Multiply the first equation by -1/3 and add the result to the second equation.
-1/3(3x -3y) +(5x -y) = -1/3(-3) +-13
4x = -12 . . . . simplify
x = -3 . . . . . . divide by 4
Substituting this into -1/3 times the first equation, we get ...
-(-3) +y = 1
y = -2 . . . . . . . subtract 3
The solution is (x, y) = (-3, -2).
