4.7 can be rewritten as 4.70 because the 0's after 7 are not significant...suppose you were measuring something and found out the item was 3.5 inches. That would be the same as 3.5000000 because the 0's are meaningless.
An equivalent expression can be found by distributing the 20 and 4 and then doing algebra.
I am not sure what we have to do with that expression...
First, you can multiply both sides by 3 to get rid of potential fractions.
From there, you have to do basic algebra.
Go to the on-site calculator and input sqrt(5).
Just multiply 1/3 and 5.7 to get your answer.
The square root of 27 is not a rational number...it can only be simplified to $$3\sqrt{3}$$ which is not rational.
For this one, you can do the following:
x^3 = 64/27.
x^3^(1/3) = (64/27)^1/3 [we are basically taking the cube root of both sides].
x = cube root of 64 / cube root of 27.
x = 4 / 3.
x = 4/3.
s = d / t.
s = 1500 km / 6.5 hours.
s = ~ 231 km/hr.
What a fast vehicle!
Just multiply: -0.0588235294117647*100 = -100/17. [The calculator on the home page will produce a fraction for you, too -- Cool, isn't it?]