Answer:
9 mph
Step-by-step explanation:
-let x be the speed of current and t be time. The speed equation for both directions can then be represented as:

#Since t is equal in both, we can do away with t.
#We the divide the downstream equation by the upstream equation as:

Hence, the boat's speed in still water is 9 mph
Answer:
1.
Variable: x
Inequality: x ≤ 12
Value that matches: 12
2.
Variable: y
Inequality: y < 66
Value that matches: 60
Step-by-step explanation:
Solving (1):
Let x be the variable
Reading through the question, we have the inequality to be represented by "at most".
At most is used for less than or equal to.
Hence, the expression can be represented by:
x ≤ 12
The range of this inequality is limited to all natural number that do not exceed 12.
Examples are 8, 2, 11, 12
Solving (2):
Let the variable be y
Reading through the question, we have the inequality to be represented by "below".
Below means less than
Hence, the expression can be represented by:
y < 66
The range of this inequality is limited to all number less than 66.
Examples are 65, 1 , 60......
Start by writing what is said:
2x + 4 = -6
From there just solve for x:
Subtract 4 from both sides
2x + 4 - 4 = -6 - 4
2x = -10
Divide by 2 to get x by itself
2x/2 = -10/2
x = -5
Answer: 7
Step-by-step explanation:
5+7+9=21
3 total numbers to start with so;
21/3=7