X miles per hour - <span> speed of the boat in still water
(x - 2) - speed up the river
(x + 2) - speed down the river
</span>

=

30 * (x + 2) = 38 * (x - 2)
30x + 60 = 38x - 76
- 8x = - 136
x =
17 miles per hour - <span>
the speed of the boat in still water.</span>
Answer:
-123
Step-by-step explanation:
The remainder theorem says that when a polynomial is divided by a linear factor x - c (note the minus sign), the remainder is the value of the polynomial at x = c.
When a polynomial P(x) is divided by x - c, the remainder is P(c). In other words, to find the remainder, plug in c for x.
You're dividing by x + 4 which is the same thing as x - (-4) -- the role of c is being played by -4.
3(–4)^3 – (–4)^2 – 20(–4) + 5 = –123
Answer:

Step-by-step explanation:
The given expression is

First, we need to factor each denominator

So, the least common factor (LCF) is
, because they are the factors that repeats.
Now, we diviide the LCF by each denominator, to then multiply it by each numerator.

Then, we factor the numerator, to do so, we need to find two numbers which product is 10 and which sum is 7.

Therefore, the expression is equivalent to

Answer:
Equivalent systems of equations review
Step-by-step explanation:
We're given two systems of equations and asked if they're equivalent.
x + 4y = 8 (1)
4x + y = 2 (2)
Interestingly, if we sum the equations in System A, we get:


Replacing the first equation in System A with this new equation, we get a system that's equivalent to System A:


This is System B, which means that System A is equivalent to System B.