-4.2 degrees. What you would do is from 8-12 (midnight) is 4 hours. So it dropped -16.8 degrees in those 4 hours so -16.8 / 4 is -4.2 degrees. So it dropped -4.2 degrees every hour but it was also -4.2 degrees at 9:00 p.m.
Problem 11
<h3>Answer: h =
2A/b</h3>
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Explanation:
We need to get h by itself. To do so, we first multiply both sides by 2. Then we divide both sides by b
A = (1/2)*b*h
2A = b*h
b*h = 2A
h = 2A/b
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Problem 12
<h3>Answers:</h3>
- Equation: (n+2)/5 = 14
- Solution to that equation: n = 68
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Explanation:
The number n is increased by 2 to get n+2
Then we divide by 5 to get (n+2)/5
This is set equal to 14 to get the equation (n+2)/5 = 14
Solving the equation would look like this
(n+2)/5 = 14
n+2 = 5*14 .... multiply both sides by 5
n+2 = 70
n = 70-2 .... subtract 2 from both sides
n = 68
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Problem 13
<h3>Answer: Not a solution</h3>
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Explanation:
We'll replace every copy of x with -3 and simplify
-2x + 5 > 13
-2*(-3) + 5 > 13
6 + 5 > 13
11 > 13
The last inequality is false because 11 is not greater than 13. Since the last inequality is false, this makes the first inequality false when x = -3.
Therefore, x = -3 is not a solution.
Remember, you can do anything to an equation as long as you do it to both sides
and when multiply or divide by a negative in inequalities, flip the direction of the sign
12x-39<9
add 39 to both sides
12x<48
divde bothh sides by 12
x<4
-4x+3<-6
minus 3 both sides
-4x<-9
times both sides by -1 and flip sign
4x>9
divide both sides by 4
x>9/4
Answer:
- 15 - 7 (Parentheses)
- 3² (Exponents)
- 8 × 2 (Multiplication)
- 40 ÷ 8 (Division)
- 5 + 9 (Addition starting from the leftmost)
- 14 + 16 (Addition after the first addition operation)
Concept:
When encountering questions that ask for simplifying expressions through operation, following the PEMDAS method would be easier:
- <u>P</u>arentheses
- <u>E</u>xponents
- <u>M</u>ultiplication
- <u>D</u>ivision
- <u>A</u>ddition
- <u>S</u>ubtraction
Therefore, the whole process of simplifying the given expression should follow the PEMDAS method. <u>For extra</u>, whenever there are two occurences of the same operation, then prioritize the leftmost and go right.
Hope this helps!! :)
Please let me know if you have any questions or need further explanation
