Answer:
(c)
"The given statement is true, by definition of length of a vector
,
"
Step-by-step explanation:
(a) 
That is completely correct Remember that if
then

Therefore the correct answer would be (c).
"The given statement is true, by definition of length of a vector
,
"
−<span>3<span>(<span><span>4a</span>−<span>5b</span></span>)</span></span><span>=<span><span>(<span>−3</span>)</span><span>(<span><span>4a</span>+<span>−<span>5b</span></span></span>)</span></span></span><span>=<span><span><span>(<span>−3</span>)</span><span>(<span>4a</span>)</span></span>+<span><span>(<span>−3</span>)</span><span>(<span>−<span>5b</span></span>)</span></span></span></span><span>=<span><span>−<span>12a</span></span>+<span>15<span>b</span></span></span></span>
24 / 30 x 100 = 80
answer: <span>Twenty-four is 30% of 80</span>
When
the ball is in the ground, its height is basically equal to zero thus making
our equation,
<span> -16t^2 + 272t + 1344 = 0</span>
Simplifying
the equation will give us,
<span> - t^2 + 17t + 84 = 0 or t^2 – 17t – 84 = 0</span>
Factoring
out the equation will give us,
<span> (t – 21)(t + 4) = 0</span>
Thus,
t = 21 or t = -4. -4 is an extraneous root. Thus, the answer is t = 21.
<span>Answer:
21 seconds</span>