A) time = distance/speed
For the first half of the trip, the time used was
.. (1 mi)/(12 mi/h) = (1/12) h = 5 minutes
Then the last half of the trip took 10 minutes, 1/6 hour.
.. speed = distance/time
.. = (1 mi)/(1/6 h) = 6 mi/h
The speed for the last half of the trip was 6 mph.
b) The average speed was
.. (2 mi)/(1/4 h) = 8 mi/h
Ling's average speed was 8 mph.
The order of arithmetic operations is given by the acronym PEMDAS, which means
Parentheses,
Exponents,
Multiplication,
Division,
Addition,
Subtraction.
These two examples illustrate how the use of parentheses can change the order.
Example 1:
5+7/3x4-2/5 has an answer of 13.933.
Use PEMDAS to obtain
5+(7/3)x4-(2/5)
= 5+(2.3333x4)-0.4
= 5+9.3333-0.4
= 14.3333-0.4
= 13.933
If we apply the parentheses: (5+7)/3x4-2/5
The result is
(12/3)x4-(2/5)
= (4x4)-0.4
= 16-0.4
= 15.06
which is a different answer.
Example 2:
8/3²x5+4 has the answer 8.444
Use PEMDAS to obtain
8/(3²)x5+4
= (8/9)x5+4
= (0.8889x5)+4
= 4.4444+4
= 8.4444
If we apply the parentheses (8/3)²x5+4:
The result is
2.6667²x5+4
= 7.1113x5+4
= 35.5565+4
= 39.5565
which is a different answer.
Answer:
p = 7
Step-by-step explanation:
set the expressions = to each other
4(n+7) = 4(n+p)
distribute the 4 on both sides(multiplying the numbers on the inside)
4n+28 = 4n+4p
subtract the 4n from the right and left
28 = 4p
divide by 4
p = 7
Tan 18 = opposite side/adjacent side
0.3249 = 4/adjacent side
and adjacent side = 4/0.3249 = 12.31
Now let's apply Pythagoras to find x
4² + 12.31² = x²
16 + 151.55 = x² and x² = 167.55
Then x = √167.55 and x = 12.94 ≈ 13
