Let the boat speed in still water be b.
Let the current speed be c.
The speed going upstream is 20/4 = 5 mph.
The speed going downstream is 32/4 = 8 mph.
b - c = 5 ........(1)
b + c = 8 .......(2)
Adding equations (1) and (2) we get:
2b = 13
b = 13/2 = 6.5
Plugging in the value for b into equation (1) we find c = 1.5.
The boat speed in still water is 6.5 mph and the current speed is 1.5 mph.
Help with what there is nothing?
Answer:
a) The correct option is C: 4x
b) The correct option is B: 2x
Step-by-step explanation:
a) Usually when we have a real number multiplying a variable, we do not need to write the multiplication symbol.
So instead of writing:
4×x
We can write:
4x
And this will be equivalent.
Then in this case the correct option is C.
b) We know that if we have the multiplication of A by n, this will be equivalent to add A n times.
Then if we have the sum of A, for example, 4 times, we have:
A + A + A + A
And this can be written as 4*A
In this case, we have the expression x + x.
So we are adding x two times, then this can be written as: 2*x, or, as we said earlier, this also can be written as 2x.
Then the correct option is option B.
Its c (9) because the opposite of -9 is 9
Yes..it does. To be a function, all the inputs (x's) have to be different numbers...there can be no repeating x's...there can be repeating outputs (y's)...just not the x's
