Answer:
A
Step-by-step explanation:
The velocity of a moving body is given by the equation:
Is the velocity is <em>positive </em>(v>0), then our object will be moving <em>forwards</em>.
And if the velocity is negative (v<0), then our object will be moving <em>backwards</em>.
We want to find between which interval(s) is the object moving backwards. Hence, the second condition. Therefore:
By substitution:
Solve. To do so, we can first solve for <em>t</em> and then test values. By factoring:
Zero Product Property:
Now, by testing values for t<1, 1<t<4, and t>4, we see that:
So, the (only) interval for which <em>v</em> is <0 is the second interval: 1<t<4.
Hence, our answer is A.
-4x+y= -9 can be turned into
y= -9 + 4x
5x+2y=3 (plug y in)
5x+2(-9+4x)=3
5x-18+8x=3
5x+8x=3+18
13x=21
divide 13 on both sides
x=1.6
Answer:
A
Step-by-step explanation:
Answer:
2. 1- Experimental probability of rolling a 4 = 40%
3. 2- Theoretical probability is 3% greater than experimental probability.
Step-by-step explanation:
Experimental probability of rolling a 4 = 100 × 
= 100 × 0.4
= 40%
Experimental probability of getting at least one tail = 
= 0.72
Theoretical probability of getting at least one tail = 
= 0.75
Theoretical probability is 3% greater than experimental probability.
Answer:
25
Step-by-step explanation:
a² + 7a + 7
a = 2
Plug in the value of 2 for every occurance of a.
(2)² + 7(2) + 7
First, solve the exponent.
4 + 7(2) + 7
Now, multiply.
4 + 14 + 7.
Add.
25
This is your answer.
Hope this helps!
