Answer:
Since the 'base' and 'top' of any prism have the same shape, the surface area can be found by
surface area of prism = 2 * area of base + perimeter of base * H
So for the rectangular prism in your example..
surface area = 2LW + 2(L+W)H
= 2 * 7 * 4 + 2*(7+4)*5
= 56 + 2 * 11 * 5
= 56 +110
= 166 sq cm
Hope this helps
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.
A₆ =12
a₇ = ?? = x
a₈ 27
In this case x is the geometric mean & as per the formula
geometric mean of 2 numbers =√(a₆ * a₈) = √(12*27)
& x=18.
Proof:
Find the common ratio between a₇ & a₆ ==> = ( x) / 12
now find the common ration between a₈ & a₇ ===> =27 / (x)
x/12 = 27/x ===> x² = 12*27 ==> x² = 324 & x =√324 = 18
Answer:
$8 per hours
Step-by-step explanation: