Answer:
Current speed is 40mph
Step-by-step explanation:
We firstly need to know what is intended by upstream and downstream. When the boat travels in the direction of the current (horizontal movement of the water), we say it is moving downstream otherwise it is moving upstream.
Let's assume the speed of the boat is A and that of the current is B, then the speed when it moves dowstream would be A + B and the speed if it moves upstream would be A – B.
In this question, we know that the speed of the boat is 40mph. Given that it takes the same time to travel 8miles upstream as it does to travel 24miles downstream, we have
Speed upstream = 8/t
Speed downstream = 24/t
Respectively.
Let speed of current be X, then
Speed downstream = 40 + X
Speed upstream = 40 – X
From the question we have:
(40 + x)/24 = (40 – X)/8
(40 + x)/3 = (40 – x)/1
3(40 – x) = 40 + X
120 – 3x = 40 – X
120 – 40 = 3x – X
2x = 80
X = 40.
Therefore, current speed is 40mph
Polynomial comes from poly- (meaning "many") and -nomial (in this case meaning "term") ... so it says "many terms"
A polynomial can have:
constants (like 3, −20, or ½)
variables (like x and y)
exponents (like the 2 in y2), but only 0, 1, 2, 3, ... etc are allowed
that can be combined using addition, subtraction, multiplication and division ...
... except ...
... not division by a variable (so something like 2/x is right out)
So:
A polynomial can have constants, variables and exponents,
but never division by a variable.
Also they can have one or more terms, but not an infinite number of terms.
These are polynomials:
3x
x − 2
−6y2 − ( 79 )x
3xyz + 3xy2z − 0.1xz − 200y + 0.5
512v5 + 99w5
5
(Yes, "5" is a polynomial, one term is allowed, and it can be just a constant!)
These are not polynomials
3xy-2 is not, because the exponent is "-2" (exponents can only be 0,1,2,...)
2/(x+2) is not, because dividing by a variable is not allowed
1/x is not either
√x is not, because the exponent is "½" (see fractional exponents)
But these are allowed:
x/2 is allowed, because you can divide by a constant
also 3x/8 for the same reason
√2 is allowed, because it is a constant (= 1.4142...etc)
Answer: x = 9
Mel's mistake was in the last step, she multiplied by 2 instead of dividing by 2
Step-by-step explanation:
2x + 1 = 19
Subtract 1 from each side
2x = 18
Divide by 2
x = 9
Answer:
I think its 55.5
Step-by-step explanation
Sorry if I got it wrong for you