Answer:
x = -7 and x = 3
Step-by-step explanation:
x² + 4x - 21 = 0 factors as follows: (x + 7)(x - 3) = 0.
Then x = -7 and x = 3.
Answer:
2
Step-by-step explanation:
Using the determinant method, the cross product is
so the answer is B.
Or you can apply the properties of the cross product. By distributivity, we have
(3i + 8j - 6k) x (-4i - 2j - 3k)
= -12(i x i) - 32(j x i) + 24(k x i) - 6(i x j) - 16(j x j) + 12(k x j) - 9(i x k) - 24(j x k) + 18(k x k)
Now recall that
- (i x i) = (j x j) = (k x k) = 0 (the zero vector)
- (i x j) = k
- (j x k) = i
- (k x i) = j
- (a x b) = -(b x a) for any two vectors a and b
Putting these rules together, we get
(3i + 8j - 6k) x (-4i - 2j - 3k)
= -32(-k) + 24j - 6k + 12(-i) - 9(-j) - 24i
= (-12 - 24)i + (24 + 9)j + (32 - 6)k
= -36i + 33j + 26k
Full question:
Linear Functions: Taking a Taxi
You take a trip to downtown Boston to walk the Freedom Trail with your family. After you walk through the Bunker Hill Memorial, your family decides to take a taxi to a restaurant for dinner. After 1 mile, the meter on the taxi says $4.75. It will cost $8.25 to go 3 miles. The cost varies linearly with the distance that you traveled. If you have $11 in your pocket, will you be able to take the cab 5 miles?
Answer:
Cannot go 5 miles having just $11
Step-by-step explanation:
Since the cost varies linearly with the distance that you traveled, to model the linear function for this problem we know that
1 mile = $4.75
And so to go x miles, we require $4.75x
Equation can therefore be modelled thus :
y=4.5x
Where y = total cost of transport in dollars
x= cost in dollars per mile
To find out if we can go 5 miles just having $11, we plug in 5 miles for x into the equation to find total cost of transport going 5 miles
y=4.5*5
y= $22.5
Therefore we cannot go 5 miles just having $11
Answer:
f(x)= -8x-3
Step-by-step explanation:
i got it right
