Answer:
729 : 9 = 80 +1 is correct
Answer: the speed of the current is 9 mph.
Step-by-step explanation:
Let x represent the speed of the current.
A boat can travel 21 mph in still water. If it travels 270 miles with the current. It means that the total speed with which the boat travelled with the current is (21 + x) mph.
Time = distance/speed
Time spent by the boat in travelling 270 miles is
270/(21 + x)
In the same length of time, it travels 108 miles against the current. It means that the total speed with which the boat travelled against the current is (21 - x) mph.
Time = distance/speed
Time spent by the boat in travelling 108 miles is
108/(21 - x)
Since the time is the same, then
270/(21 + x) = 108/(21 - x)
270(21 - x) = 108(21 + x)
5670 - 270x = 2268 - 108x
108x + 270x = 5670 - 2268
378x = 3402
x = 3402/378
x = 9
The equivalent expression of (8x)^-2/3 * (27x)^-1/3 is 1/12x
<h3>How to evaluate the expression?</h3>
The expression is given as:
(8x)^-2/3 * (27x)^-1/3
Evaluate the exponent 8^-2/3
(8x)^-2/3 * (27x)^-1/3 = 1/4(x)^-2/3 * (27x)^-1/3
Evaluate the exponent (27x)^-1/3
(8x)^-2/3 * (27x)^-1/3 = 1/4(x)^-2/3 * 1/3(x)^-1/3
Multiply 1/4 and 1/3
(8x)^-2/3 * (27x)^-1/3 = 1/12(x)^-2/3 * (x)^-1/3
Evaluate the exponent
(8x)^-2/3 * (27x)^-1/3 = 1/12(x)^(-2/3 -1/3)
This gives
(8x)^-2/3 * (27x)^-1/3 = 1/12(x)^(-1)
So, we have
(8x)^-2/3 * (27x)^-1/3 = 1/12x
Hence, the equivalent expression of (8x)^-2/3 * (27x)^-1/3 is 1/12x
Read more about equivalent expression at
brainly.com/question/2972832
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Answer:
The length of diagonal d is 14.1421 cm
Step-by-step explanation:
We are given square
Length of side of square = 10 cm
We need to find the length of diagonal d
To find diagonal of square, the formula used is:
where s is length of side of square.
Putting values of s and finding length of diagonal of square
So, The length of diagonal d is 14.1421 cm
Answer:
a and b.
Step-by-step explanation:
I’ll explain by giving an example.
Let’s say that: a=3;b=4;c=5; => they all are consecutive -> their sum is 12.
=> if we use a) n=3 => 3*n+3=3*3+3=12 => correct.
b) n+(n+1)+(n+2)= 3+4+5=12=> correct.
c)n+2n+3n=3+6+9=18=>incorrect.
d)3n=3*3=9=>incorrect.