Answer:
3
Step-by-step explanation:
(32-20)÷4
solve perentisis first
(12)÷4
now divide
=3
There are 6 balls to every box (a ratio of 6 to 1). Therefore, when there are 78 balls, there are 13 boxes.
Divide through everything by <em>b</em> :

Since <em>a/b</em> < <em>c/d</em>, it follows that

Multiply through everything on the right side by <em>b/d</em> to get

and so (<em>a</em> + <em>c</em>)/(<em>b</em> + <em>d</em>) < <em>c/d</em>.
For the other side, you can do something similar and divide through everything by <em>d</em> :

and <em>a/b</em> < <em>c/d</em> tells us that

Then

and so (<em>a</em> + <em>c</em>)/(<em>b</em> + <em>d</em>) > <em>a/b</em>.
Then together we get the desired inequality.
Answer:
rate of the plane in still air is 33 miles per hour and the rate of the wind is 11 miles per hour
Step-by-step explanation:
We will make a table of the trip there and back using the formula distance = rate x time
d = r x t
there
back
The distance there and back is 264 miles, so we can split that in half and put each half under d:
d = r x t
there 132
back 132
It tells us that the trip there is with the wind and the trip back is against the wind:
d = r x t
there 132 = (r + w)
back 132 = (r - w)
Finally, the trip there took 3 hours and the trip back took 6:
d = r * t
there 132 = (r + w) * 3
back 132 = (r - w) * 6
There's the table. Using the distance formula we have 2 equations that result from that info:
132 = 3(r + w) and 132 = 6(r - w)
We are looking to solve for both r and w. We have 2 equations with 2 unknowns, so we will solve the first equation for r, sub that value for r into the second equation to solve for w:
132 = 3r + 3w and
132 - 3w = 3r so
44 - w = r. Subbing that into the second equation:
132 = 6(44 - w) - 6w and
132 = 264 - 6w - 6w and
-132 = -12w so
w = 11
Subbing w in to solve for r:
132 = 3r + 3(11) and
132 = 3r + 33 so
99 = 3r and
r = 33
Answer:
A
Step-by-step explanation:
Given
x² + 6x
To complete the square
add ( half the coefficient of the x- term )² to x² + 6x
x² + 6x + (3)²
= x² + 6x + 9
= (x + 3)²