Answer: A; 6.3%
Step-by-step explanation:
Problem 1
For the first problem, we first want to find y so that we can plug it into the expression.
We can use elimination method for the system of equations to solve.
3x+3y=21
3x-y=5
We subtract both equations to eliminate x.
4y=16 [divide both sides by 4]
y=4
Now that we know y, we can plug it into the expression.
[divide]
[subtract]

We know that the answer is A.
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Problem 2
For the second problem, we need to know how to calculate percent error. The formula for precent error is
. We know that the exact value is 80 because the buyer was supposed to given 80. 75 is the measured value because that was what the buyer was given.
[subtract]
[solve absolue value]
[divide]
[multiply]

Since the problem said to round to one decimal place, we know that the answer is 6.3%.
Answer:
4 1/2
Step-by-step explanation:
Just do the math work it out on paper and check it!
Answer:
u ≤ 4
Step-by-step explanation:
The given inequality
15 ≤ 39 - 6u
Subtract 39 from both sides, we get
15 - 39 ≤ 39 - 6u - 39
-24 ≤ -6u
Dividing both sides by -6, we get
4 ≥ u [Remember, when we divide by negative, the direction of
the inequality changes]
Which is u ≤ 4.
Thank you.
Answer:
Can't guess whether you have written 'x' or you have put a sign of multiplication!!
Based on the starting temperature and the new temperature, the relevant expression would be<u> 2 - (-9) </u>
To find the number of degrees the temperature has changed by, use the following equation:
<em>= Starting temperature - Current temperature </em>
Starting temperature = 2°F
Current temperature = -9°F
The equation becomes:
<em>= 2 - (-9)</em>
In conclusion, the expression would be 2 - (-9)
<em>Find out more on </em><em>expressions </em><em>at brainly.com/question/945593. </em>