The <em>correct answers</em> are:
5x²+70x+245 ≥ 1050; and
Yes.
Explanation:
Let x be the width of the tablet. Since the width of the TV is 7 inches more than the tablet, the width of the TV would be x+7.
The length of the TV is 5 times the width; this makes the length 5(x+7) = 5x+35.
The area of the TV would be given by
(x+7)(5x+35).
Since Andrew wants the area to be at least 1050, we set the expression greater than or equal to 1050:
(x+7)(5x+35) ≥ 1050
Multiplying this, we have:
x*5x+x*35+7*5x+7*35 ≥ 1050
5x²+35x+35x+245 ≥ 1050
Combining like terms,
5x²+70x+245 ≥ 1050
To see if 8 is a reasonable width for the tablet, we substitute 8 for x:
5(8²)+70(8)+245 ≥ 1050
5(64)+560+245 ≥ 1050
320+560+245 ≥ 1050
1125 ≥ 1050
Since this inequality is true, 8 is a reasonable width.
Answer: (a, 0)
<u>Step-by-step explanation:</u>
Notice that S is on the x-axis, therefore the y-coordinate is "0".
Notice that S has the same x-value of R. The x-value of R is "a".
Answer:
20/81
Step-by-step explanation:
Without parentheses, it is hard to tell what you are dividing. We assume you want ...
(4/9)/(9/5)
Then ...
_____
As written (without parentheses), your expression is evaluated left to right, so evaluates to ...
4/(9·9·5) = 4/405
Answer:
it is A
Step-by-step explanation:
A
<u>Question 1 solution:</u>
You have two unknowns here:
Let the Water current speed = W
Let Rita's average speed = R
We are given <em>two </em>situations, where we can form <em>two equations</em>, and therefore solve for the <em>two unknowns, W, R</em>:
Part 1) W→ , R←(against current, upstream)
If Rita is paddling at 2mi/hr against the current, this means that the current is trying to slow her down. If you look at the direction of the water, it is "opposing" Rita, it is "opposite", therefore, our equation must have a negative sign for water<span>:
</span>R–W=2 - equation 1
Part 2) W→ , R<span>→</span>(with current)
Therefore, R+W=3 - equation 2
From equation 1, W=R-2,
Substitute into equation 2.
R+(R–2)=3
2R=5
R=5/2mi/hr
So when W=0 (still), R=5/2mi/hr
Finding the water speed using the same rearranging and substituting process:
1... R=2+W
2... (2+W)+W=3
2W=1
W=1/2mi/hr
